Font Color

Color, as a topic, extends beyond the Font object; font color is just the first place it’s come up. Accordingly, it bears a little deeper thought than usual since we’ll want to reuse the same objects and protocol to specify color in the other contexts; it makes sense to craft a general solution that will bear the expected reuse.

There are three historical sources to draw from for this API.

  1. The w:rPr/w:color element. This is used by default when applying color directly to text or when setting the text color of a style. This corresponds to the Font.Color property (undocumented, unfortunately). This element supports RGB colors, theme colors, and a tint or shade of a theme color.
  2. The w:rPr/w14:textFill element. This is used by Word for fancy text like gradient and shadow effects. This corresponds to the Font.Fill property.
  3. The PowerPoint font color UI. This seems like a reasonable compromise between the prior two, allowing direct-ish access to common color options while holding the door open for the Font.fill operations to be added later if required.

Candidate Protocol

docx.text.run.Run has a font property:

>>> from docx import Document
>>> from docx.text.run import Font, Run
>>> run = Document().add_paragraph().add_run()
>>> isinstance(run, Run)
True
>>> font = run.font
>>> isinstance(font, Font)
True

docx.text.run.Font has a read-only color property, returning a docx.dml.color.ColorFormat object:

>>> from docx.dml.color import ColorFormat
>>> color = font.color
>>> isinstance(font.color, ColorFormat)
True
>>> font.color = 'anything'
AttributeError: can't set attribute

docx.dml.color.ColorFormat has a read-only type property and read/write rgb, theme_color, and brightness properties.

ColorFormat.type returns one of MSO_COLOR_TYPE.RGB, MSO_COLOR_TYPE.THEME, MSO_COLOR_TYPE.AUTO, or None, the latter indicating font has no directly-applied color:

>>> font.color.type
None

ColorFormat.rgb returns an RGBColor object when type is MSO_COLOR_TYPE.RGB. It may also report an RGBColor value when type is MSO_COLOR_TYPE.THEME, since an RGB color may also be present in that case. According to the spec, the RGB color value is ignored when a theme color is specified, but Word writes the current RGB value of the theme color along with the theme color name (e.g. ‘accent1’) when assigning a theme color; perhaps as a convenient value for a file browser to use. The value of .type must be consulted to determine whether the RGB value is operative or a “best-guess”:

>>> font.color.type
RGB (1)
>>> font.color.rgb
RGBColor(0x3f, 0x2c, 0x36)

Assigning an RGBColor value to ColorFormat.rgb causes ColorFormat.type to become MSO_COLOR_TYPE.RGB:

>>> font.color.type
None
>>> font.color.rgb = RGBColor(0x3f, 0x2c, 0x36)
>>> font.color.type
RGB (1)
>>> font.color.rgb
RGBColor(0x3f, 0x2c, 0x36)

ColorFormat.theme_color returns a member of MSO_THEME_COLOR_INDEX when type is MSO_COLOR_TYPE.THEME:

>>> font.color.type
THEME (2)
>>> font.color.theme_color
ACCENT_1 (5)

Assigning a member of MSO_THEME_COLOR_INDEX to ColorFormat.theme_color causes ColorFormat.type to become MSO_COLOR_TYPE.THEME:

>>> font.color.type
RGB (1)
>>> font.color.theme_color = MSO_THEME_COLOR.ACCENT_2
>>> font.color.type
THEME (2)
>>> font.color.theme_color
ACCENT_2 (6)

The ColorFormat.brightness attribute can be used to select a tint or shade of a theme color. Assigning the value 0.1 produces a color 10% brighter (a tint); assigning -0.1 produces a color 10% darker (a shade):

>>> font.color.type
None
>>> font.color.brightness
0.0
>>> font.color.brightness = 0.4
ValueError: not a theme color

>>> font.color.theme_color = MSO_THEME_COLOR.TEXT_1
>>> font.color.brightness = 0.4
>>> font.color.brightness
0.4

Specimen XML

Baseline paragraph with no font color:

<w:p>
  <w:r>
    <w:t>Text with no color.</w:t>
  </w:r>
</w:p>

Paragraph with directly-applied RGB color:

<w:p>
  <w:pPr>
    <w:rPr>
      <w:color w:val="0000FF"/>
    </w:rPr>
  </w:pPr>
  <w:r>
    <w:rPr>
      <w:color w:val="0000FF"/>
    </w:rPr>
    <w:t>Directly-applied color Blue.</w:t>
  </w:r>
</w:p>

Run with directly-applied theme color:

<w:r>
  <w:rPr>
    <w:color w:val="4F81BD" w:themeColor="accent1"/>
  </w:rPr>
  <w:t>Theme color Accent 1.</w:t>
</w:r>

Run with 40% tint of Text 2 theme color:

<w:r>
  <w:rPr>
    <w:color w:val="548DD4" w:themeColor="text2" w:themeTint="99"/>
  </w:rPr>
  <w:t>Theme color with 40% tint.</w:t>
</w:r>

Run with 25% shade of Accent 2 theme color:

<w:r>
  <w:rPr>
    <w:color w:val="943634" w:themeColor="accent2" w:themeShade="BF"/>
  </w:rPr>
  <w:t>Theme color with 25% shade.</w:t>
</w:r>

Schema excerpt

<xsd:complexType name="CT_RPr">  <!-- denormalized -->
  <xsd:sequence>
    <xsd:choice minOccurs="0" maxOccurs="unbounded"/>
      <xsd:element name="rStyle"          type="CT_String"/>
      <xsd:element name="rFonts"          type="CT_Fonts"/>
      <xsd:element name="b"               type="CT_OnOff"/>
      <xsd:element name="bCs"             type="CT_OnOff"/>
      <xsd:element name="i"               type="CT_OnOff"/>
      <xsd:element name="iCs"             type="CT_OnOff"/>
      <xsd:element name="caps"            type="CT_OnOff"/>
      <xsd:element name="smallCaps"       type="CT_OnOff"/>
      <xsd:element name="strike"          type="CT_OnOff"/>
      <xsd:element name="dstrike"         type="CT_OnOff"/>
      <xsd:element name="outline"         type="CT_OnOff"/>
      <xsd:element name="shadow"          type="CT_OnOff"/>
      <xsd:element name="emboss"          type="CT_OnOff"/>
      <xsd:element name="imprint"         type="CT_OnOff"/>
      <xsd:element name="noProof"         type="CT_OnOff"/>
      <xsd:element name="snapToGrid"      type="CT_OnOff"/>
      <xsd:element name="vanish"          type="CT_OnOff"/>
      <xsd:element name="webHidden"       type="CT_OnOff"/>
      <xsd:element name="color"           type="CT_Color"/>
      <xsd:element name="spacing"         type="CT_SignedTwipsMeasure"/>
      <xsd:element name="w"               type="CT_TextScale"/>
      <xsd:element name="kern"            type="CT_HpsMeasure"/>
      <xsd:element name="position"        type="CT_SignedHpsMeasure"/>
      <xsd:element name="sz"              type="CT_HpsMeasure"/>
      <xsd:element name="szCs"            type="CT_HpsMeasure"/>
      <xsd:element name="highlight"       type="CT_Highlight"/>
      <xsd:element name="u"               type="CT_Underline"/>
      <xsd:element name="effect"          type="CT_TextEffect"/>
      <xsd:element name="bdr"             type="CT_Border"/>
      <xsd:element name="shd"             type="CT_Shd"/>
      <xsd:element name="fitText"         type="CT_FitText"/>
      <xsd:element name="vertAlign"       type="CT_VerticalAlignRun"/>
      <xsd:element name="rtl"             type="CT_OnOff"/>
      <xsd:element name="cs"              type="CT_OnOff"/>
      <xsd:element name="em"              type="CT_Em"/>
      <xsd:element name="lang"            type="CT_Language"/>
      <xsd:element name="eastAsianLayout" type="CT_EastAsianLayout"/>
      <xsd:element name="specVanish"      type="CT_OnOff"/>
      <xsd:element name="oMath"           type="CT_OnOff"/>
    </xsd:choice>
    <xsd:element name="rPrChange" type="CT_RPrChange" minOccurs="0"/>
  </xsd:sequence>
</xsd:group>

<xsd:complexType name="CT_Color">
  <xsd:attribute name="val"        type="ST_HexColor" use="required"/>
  <xsd:attribute name="themeColor" type="ST_ThemeColor"/>
  <xsd:attribute name="themeTint"  type="ST_UcharHexNumber"/>
  <xsd:attribute name="themeShade" type="ST_UcharHexNumber"/>
</xsd:complexType>

<!-- simple types -->

<xsd:simpleType name="ST_HexColor">
  <xsd:union memberTypes="ST_HexColorAuto s:ST_HexColorRGB"/>
</xsd:simpleType>

<xsd:simpleType name="ST_HexColorAuto">
  <xsd:restriction base="xsd:string">
    <xsd:enumeration value="auto"/>
  </xsd:restriction>
</xsd:simpleType>

<xsd:simpleType name="ST_HexColorRGB">
  <xsd:restriction base="xsd:hexBinary">
    <xsd:length value="3" fixed="true"/>
  </xsd:restriction>
</xsd:simpleType>

<xsd:simpleType name="ST_ThemeColor">
  <xsd:restriction base="xsd:string">
    <xsd:enumeration value="dark1"/>
    <xsd:enumeration value="light1"/>
    <xsd:enumeration value="dark2"/>
    <xsd:enumeration value="light2"/>
    <xsd:enumeration value="accent1"/>
    <xsd:enumeration value="accent2"/>
    <xsd:enumeration value="accent3"/>
    <xsd:enumeration value="accent4"/>
    <xsd:enumeration value="accent5"/>
    <xsd:enumeration value="accent6"/>
    <xsd:enumeration value="hyperlink"/>
    <xsd:enumeration value="followedHyperlink"/>
    <xsd:enumeration value="none"/>
    <xsd:enumeration value="background1"/>
    <xsd:enumeration value="text1"/>
    <xsd:enumeration value="background2"/>
    <xsd:enumeration value="text2"/>
  </xsd:restriction>
</xsd:simpleType>

<xsd:simpleType name="ST_UcharHexNumber">
  <xsd:restriction base="xsd:hexBinary">
    <xsd:length value="1"/>
  </xsd:restriction>
</xsd:simpleType>