diff --git a/docx-core/src/documents/content_types.rs b/docx-core/src/documents/content_types.rs
index 6770c9f..8775fac 100644
--- a/docx-core/src/documents/content_types.rs
+++ b/docx-core/src/documents/content_types.rs
@@ -55,6 +55,8 @@ impl BuildXML for ContentTypes {
 mod tests {
 
     use super::*;
+    #[cfg(test)]
+    use pretty_assertions::assert_eq;
     use std::str;
 
     #[test]
diff --git a/docx-core/src/documents/elements/color.rs b/docx-core/src/documents/elements/color.rs
new file mode 100644
index 0000000..36d5667
--- /dev/null
+++ b/docx-core/src/documents/elements/color.rs
@@ -0,0 +1,34 @@
+use crate::documents::BuildXML;
+use crate::xml_builder::*;
+
+pub struct Color {
+    val: String,
+}
+
+impl Color {
+    pub fn new(val: impl Into<String>) -> Color {
+        Color { val: val.into() }
+    }
+}
+
+impl BuildXML for Color {
+    fn build(&self) -> Vec<u8> {
+        XMLBuilder::new().color(&self.val).build()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+
+    use super::*;
+    #[cfg(test)]
+    use pretty_assertions::assert_eq;
+    use std::str;
+
+    #[test]
+    fn test_build() {
+        let c = Color::new("FFFFFF");
+        let b = c.build();
+        assert_eq!(str::from_utf8(&b).unwrap(), r#"<w:color w:val="FFFFFF" />"#);
+    }
+}
diff --git a/docx-core/src/documents/elements/doc_defaults.rs b/docx-core/src/documents/elements/doc_defaults.rs
index c8334c6..294cc36 100644
--- a/docx-core/src/documents/elements/doc_defaults.rs
+++ b/docx-core/src/documents/elements/doc_defaults.rs
@@ -19,9 +19,8 @@ impl DocDefaults {
 impl BuildXML for DocDefaults {
     fn build(&self) -> Vec<u8> {
         let b = XMLBuilder::new();
-        let run_property_default = self.run_property_default.build();
         b.open_doc_defaults()
-            .add_child_buffer(&run_property_default)
+            .add_child(&self.run_property_default)
             .close()
             .build()
     }
diff --git a/docx-core/src/documents/elements/mod.rs b/docx-core/src/documents/elements/mod.rs
index 363f96b..45c41ce 100644
--- a/docx-core/src/documents/elements/mod.rs
+++ b/docx-core/src/documents/elements/mod.rs
@@ -1,4 +1,5 @@
 mod based_on;
+mod color;
 mod doc_defaults;
 mod name;
 mod next;
@@ -10,6 +11,7 @@ mod style;
 mod sz;
 
 pub use based_on::*;
+pub use color::*;
 pub use doc_defaults::*;
 pub use name::*;
 pub use next::*;
diff --git a/docx-core/src/documents/elements/paragraph_property.rs b/docx-core/src/documents/elements/paragraph_property.rs
index 29071ac..e1a9f52 100644
--- a/docx-core/src/documents/elements/paragraph_property.rs
+++ b/docx-core/src/documents/elements/paragraph_property.rs
@@ -25,6 +25,8 @@ impl BuildXML for ParagraphProperty {
 mod tests {
 
     use super::*;
+    #[cfg(test)]
+    use pretty_assertions::assert_eq;
     use std::str;
 
     #[test]
diff --git a/docx-core/src/documents/elements/run_property.rs b/docx-core/src/documents/elements/run_property.rs
index 3b704ff..d1df540 100644
--- a/docx-core/src/documents/elements/run_property.rs
+++ b/docx-core/src/documents/elements/run_property.rs
@@ -1,32 +1,45 @@
-use super::Sz;
+use super::{Color, Sz};
 use crate::documents::BuildXML;
 use crate::xml_builder::*;
 
 pub struct RunProperty {
     sz: Option<Sz>,
+    color: Option<Color>,
 }
 
 impl RunProperty {
     pub fn new() -> RunProperty {
-        RunProperty { sz: None }
+        Default::default()
     }
 
-    pub fn add_sz(mut self, sz: Sz) -> RunProperty {
-        self.sz = Some(sz);
+    pub fn add_sz(mut self, sz: usize) -> RunProperty {
+        self.sz = Some(Sz::new(sz));
         self
     }
+
+    pub fn add_color(mut self, color: &str) -> RunProperty {
+        self.color = Some(Color::new(color));
+        self
+    }
+}
+
+impl Default for RunProperty {
+    fn default() -> Self {
+        Self {
+            sz: None,
+            color: None,
+        }
+    }
 }
 
 impl BuildXML for RunProperty {
     fn build(&self) -> Vec<u8> {
         let b = XMLBuilder::new();
-        let b = b.open_run_property();
-        let b = if let Some(sz) = &self.sz {
-            b.add_child_buffer(&sz.build())
-        } else {
-            b
-        };
-        b.close().build()
+        b.open_run_property()
+            .add_optional_child(&self.sz)
+            .add_optional_child(&self.color)
+            .close()
+            .build()
     }
 }
 
@@ -40,11 +53,11 @@ mod tests {
 
     #[test]
     fn test_build() {
-        let c = RunProperty::new().add_sz(Sz::new(10));
+        let c = RunProperty::new().add_sz(10).add_color("FFFFFF");
         let b = c.build();
         assert_eq!(
             str::from_utf8(&b).unwrap(),
-            r#"<w:rPr><w:sz w:val="10" /></w:rPr>"#
+            r#"<w:rPr><w:sz w:val="10" /><w:color w:val="FFFFFF" /></w:rPr>"#
         );
     }
 }
diff --git a/docx-core/src/documents/elements/run_property_default.rs b/docx-core/src/documents/elements/run_property_default.rs
index 4d90e7d..9f509fb 100644
--- a/docx-core/src/documents/elements/run_property_default.rs
+++ b/docx-core/src/documents/elements/run_property_default.rs
@@ -16,9 +16,8 @@ impl RunPropertyDefault {
 impl BuildXML for RunPropertyDefault {
     fn build(&self) -> Vec<u8> {
         let b = XMLBuilder::new();
-        let run_property = self.run_property.build();
         b.open_run_property_default()
-            .add_child_buffer(&run_property)
+            .add_child(&self.run_property)
             .close()
             .build()
     }
@@ -28,6 +27,8 @@ impl BuildXML for RunPropertyDefault {
 mod tests {
 
     use super::*;
+    #[cfg(test)]
+    use pretty_assertions::assert_eq;
     use std::str;
 
     #[test]
diff --git a/docx-core/src/documents/elements/style.rs b/docx-core/src/documents/elements/style.rs
index 9e1acb6..f59eb4c 100644
--- a/docx-core/src/documents/elements/style.rs
+++ b/docx-core/src/documents/elements/style.rs
@@ -11,18 +11,14 @@ pub struct Style {
     paragraph_property: ParagraphProperty,
 }
 
-impl Style {
-    pub fn new(
-        style_id: impl Into<String>,
-        name: impl Into<String>,
-        style_type: StyleType,
-    ) -> Style {
-        let name = Name::new(name.into());
+impl Default for Style {
+    fn default() -> Style {
+        let name = Name::new("");
         let rpr = RunProperty::new();
         let ppr = ParagraphProperty::new();
         Style {
-            style_id: style_id.into(),
-            style_type,
+            style_id: "".to_owned(),
+            style_type: StyleType::Paragraph,
             name,
             run_property: rpr,
             paragraph_property: ppr,
@@ -30,22 +26,34 @@ impl Style {
     }
 }
 
+impl Style {
+    pub fn new(
+        style_id: impl Into<String>,
+        name: impl Into<String>,
+        style_type: StyleType,
+    ) -> Style {
+        let name = Name::new(name.into());
+        let default = Default::default();
+        Style {
+            style_id: style_id.into(),
+            style_type,
+            name,
+            ..default
+        }
+    }
+}
+
 impl BuildXML for Style {
     fn build(&self) -> Vec<u8> {
         let b = XMLBuilder::new();
-        let name = self.name.build();
-        let rpr = self.run_property.build();
-        let ppr = self.paragraph_property.build();
-        let based_on = BasedOn::new("Normal").build();
-        let next = Next::new("Normal").build();
-        let q_format = QFormat::new().build();
+        // Set "Normal" as default if you need change these values please fix it
         b.open_style(self.style_type, &self.style_id)
-            .add_child_buffer(&name)
-            .add_child_buffer(&rpr)
-            .add_child_buffer(&ppr)
-            .add_child_buffer(&based_on)
-            .add_child_buffer(&next)
-            .add_child_buffer(&q_format)
+            .add_child(&self.name)
+            .add_child(&self.run_property)
+            .add_child(&self.paragraph_property)
+            .add_child(&BasedOn::new("Normal"))
+            .add_child(&Next::new("Normal"))
+            .add_child(&QFormat::new())
             .close()
             .build()
     }
diff --git a/docx-core/src/documents/mod.rs b/docx-core/src/documents/mod.rs
index 0903d2c..894d7d2 100644
--- a/docx-core/src/documents/mod.rs
+++ b/docx-core/src/documents/mod.rs
@@ -3,14 +3,17 @@ mod content_types;
 mod doc_props;
 mod elements;
 mod rels;
+mod styles;
 mod xml_document;
 
 pub(crate) use build_xml::*;
 
+use crate::xml_builder::*;
 use content_types::*;
 use doc_props::*;
 use elements::*;
 use rels::*;
+use styles::*;
 
 pub(crate) struct Document {
     content_type: ContentTypes,
diff --git a/docx-core/src/documents/rels.rs b/docx-core/src/documents/rels.rs
index 01508bf..7593718 100644
--- a/docx-core/src/documents/rels.rs
+++ b/docx-core/src/documents/rels.rs
@@ -39,6 +39,8 @@ mod tests {
 
     use super::*;
     use std::str;
+    #[cfg(test)]
+    use pretty_assertions::assert_eq;
 
     #[test]
     fn test_build() {
diff --git a/docx-core/src/documents/styles.rs b/docx-core/src/documents/styles.rs
new file mode 100644
index 0000000..88d7aa5
--- /dev/null
+++ b/docx-core/src/documents/styles.rs
@@ -0,0 +1,59 @@
+use crate::documents::BuildXML;
+use crate::xml_builder::*;
+
+use super::{DocDefaults, Style, StyleType};
+
+pub struct Styles {
+    doc_defaults: DocDefaults,
+    styles: Vec<Style>,
+}
+
+impl Styles {
+    pub fn new() -> Styles {
+        Default::default()
+    }
+
+    pub fn add_style(mut self, style: Style) -> Self {
+        self.styles.push(style);
+        self
+    }
+}
+
+impl Default for Styles {
+    fn default() -> Self {
+        Self {
+            doc_defaults: DocDefaults::new(),
+            styles: vec![],
+        }
+    }
+}
+
+impl BuildXML for Styles {
+    fn build(&self) -> Vec<u8> {
+        let b = XMLBuilder::new();
+        b.open_styles()
+            .add_child(&self.doc_defaults)
+            .add_children(&self.styles)
+            .close()
+            .build()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+
+    use super::*;
+    #[cfg(test)]
+    use pretty_assertions::assert_eq;
+    use std::str;
+
+    #[test]
+    fn test_build() {
+        let c = Styles::new().add_style(Style::new("Title", "TitleName", StyleType::Paragraph));
+        let b = c.build();
+        assert_eq!(
+            str::from_utf8(&b).unwrap(),
+            r#"<w:styles xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships" xmlns:w="http://schemas.openxmlformats.org/wordprocessingml/2006/main" xmlns:w14="http://schemas.microsoft.com/office/word/2010/wordml" xmlns:w15="http://schemas.microsoft.com/office/word/2012/wordml" mc:Ignorable="w14 w15"><w:docDefaults><w:rPrDefault><w:rPr /></w:rPrDefault></w:docDefaults><w:style w:type="paragraph" w:styleId="Title"><w:name w:val="TitleName" /><w:rPr /><w:pPr /><w:basedOn w:val="Normal" /><w:next w:val="Normal" /><w:qFormat /></w:style></w:styles>"#
+        );
+    }
+}
diff --git a/docx-core/src/xml_builder/elements/color.rs b/docx-core/src/xml_builder/elements/color.rs
new file mode 100644
index 0000000..03fa1fb
--- /dev/null
+++ b/docx-core/src/xml_builder/elements/color.rs
@@ -0,0 +1,28 @@
+use super::XMLBuilder;
+use super::XmlEvent;
+
+impl XMLBuilder {
+    // i.e. <w:color ... >
+    pub(crate) fn color(mut self, val: &str) -> Self {
+        self.writer
+            .write(XmlEvent::start_element("w:color").attr("w:val", val))
+            .expect("should write to buf");
+        self.close()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+
+    use super::*;
+    #[cfg(test)]
+    use pretty_assertions::assert_eq;
+    use std::str;
+
+    #[test]
+    fn test_color() {
+        let b = XMLBuilder::new();
+        let r = b.color("2E74B5").build();
+        assert_eq!(str::from_utf8(&r).unwrap(), r#"<w:color w:val="2E74B5" />"#);
+    }
+}
diff --git a/docx-core/src/xml_builder/elements/mod.rs b/docx-core/src/xml_builder/elements/mod.rs
index 7d69ea5..8744ef7 100644
--- a/docx-core/src/xml_builder/elements/mod.rs
+++ b/docx-core/src/xml_builder/elements/mod.rs
@@ -2,6 +2,7 @@
 mod macros;
 
 mod based_on;
+mod color;
 mod doc_defaults;
 mod name;
 mod next;
@@ -13,6 +14,7 @@ mod style;
 mod sz;
 
 pub use based_on::*;
+pub use color::*;
 pub use doc_defaults::*;
 pub use name::*;
 pub use next::*;
diff --git a/docx-core/src/xml_builder/mod.rs b/docx-core/src/xml_builder/mod.rs
index 3d6474c..e0254a0 100644
--- a/docx-core/src/xml_builder/mod.rs
+++ b/docx-core/src/xml_builder/mod.rs
@@ -6,7 +6,9 @@ mod declaration;
 mod elements;
 mod properties;
 mod relationship;
+mod styles;
 
+use crate::BuildXML;
 use std::str;
 use xml::common::XmlVersion;
 use xml::writer::{EmitterConfig, EventWriter, XmlEvent};
@@ -50,12 +52,36 @@ impl XMLBuilder {
         self.close()
     }
 
-    pub(crate) fn add_child_buffer(mut self, buf: &[u8]) -> Self {
-        let text = str::from_utf8(buf).unwrap();
+    pub(crate) fn add_child<T>(mut self, child: &T) -> Self
+    where
+        T: BuildXML,
+    {
+        let buf = child.build();
+        let text = str::from_utf8(&buf).unwrap();
         self.writer.write(text).expect("should write to buf");
         self
     }
 
+    pub(crate) fn add_optional_child<T>(mut self, child: &Option<T>) -> Self
+    where
+        T: BuildXML,
+    {
+        if let Some(c) = child {
+            self = self.add_child(c)
+        }
+        self
+    }
+
+    pub(crate) fn add_children<T>(mut self, children: &[T]) -> Self
+    where
+        T: BuildXML,
+    {
+        for c in children {
+            self = self.add_child(c);
+        }
+        self
+    }
+
     // Close tag
     pub(crate) fn close(mut self) -> Self {
         self.writer
diff --git a/docx-core/src/xml_builder/styles.rs b/docx-core/src/xml_builder/styles.rs
new file mode 100644
index 0000000..ecfa9cf
--- /dev/null
+++ b/docx-core/src/xml_builder/styles.rs
@@ -0,0 +1,57 @@
+use std::fmt;
+
+use super::XMLBuilder;
+use super::XmlEvent;
+
+impl XMLBuilder {
+    // Build w:style element
+    // i.e. <w:styles ... >
+    pub(crate) fn open_styles(mut self) -> Self {
+        self.writer
+            .write(
+                XmlEvent::start_element("w:styles")
+                    .attr(
+                        "xmlns:mc",
+                        "http://schemas.openxmlformats.org/markup-compatibility/2006",
+                    )
+                    .attr(
+                        "xmlns:r",
+                        "http://schemas.openxmlformats.org/officeDocument/2006/relationships",
+                    )
+                    .attr(
+                        "xmlns:w",
+                        "http://schemas.openxmlformats.org/wordprocessingml/2006/main",
+                    )
+                    .attr(
+                        "xmlns:w14",
+                        "http://schemas.microsoft.com/office/word/2010/wordml",
+                    )
+                    .attr(
+                        "xmlns:w15",
+                        "http://schemas.microsoft.com/office/word/2012/wordml",
+                    )
+                    .attr("mc:Ignorable", "w14 w15"),
+            )
+            .expect("should write to buf");
+        self
+    }
+}
+
+#[cfg(test)]
+mod tests {
+
+    use super::*;
+    #[cfg(test)]
+    use pretty_assertions::assert_eq;
+    use std::str;
+
+    #[test]
+    fn test_declaration() {
+        let b = XMLBuilder::new();
+        let r = b.open_styles().close().build();
+        assert_eq!(
+            str::from_utf8(&r).unwrap(),
+            r#"<w:styles xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships" xmlns:w="http://schemas.openxmlformats.org/wordprocessingml/2006/main" xmlns:w14="http://schemas.microsoft.com/office/word/2010/wordml" xmlns:w15="http://schemas.microsoft.com/office/word/2012/wordml" mc:Ignorable="w14 w15" />"#
+        );
+    }
+}