Change Theme Base Color and Font Settings

• Feb 15, 2023
• 5 minutes to read

We introduced an option to modify a theme’s base color (for certain themes) and font settings in v16.2.

Available API

The following API enables you to change a theme’s base color and font settings declaratively in the web.config file or programmatically at runtime.

Web.config Options

baseColor

Specifies the name of a theme’s base color that is globally applied to all DevExpress controls within a website. Refer to the following help topic to learn more: Theme Base Color.

font

Specifies font settings for a theme that is globally applied to all DevExpress controls within a website. See the following topic for more information: Theme Font Settings.

XML

<configuration>
    ...
    <devExpress>
        ...
        <themes enableThemesAssembly="true" styleSheetTheme="" theme="Metropolis" 
            customThemeAssemblies="" baseColor="Green" font="30px 'Calibri'"  />
        ...
    </devExpress>
    ...
</configuration>

Programmatic API

ASPxWebControl.GlobalThemeBaseColor

Gets or sets the base color for the theme to be globally applied to all DevExpress web controls across a web page or entire web site.

ASPxWebControl.GlobalThemeFont

Gets or sets the font settings of the theme to be globally applied to all DevExpress web controls across a web page or entire web site.

C#

protected void Application_PreRequestHandlerExecute(object sender, EventArgs e) {
    // ...
    DevExpress.Web.ASPxWebControl.GlobalThemeBaseColor = "Green";
    DevExpress.Web.ASPxWebControl.GlobalThemeFont = "30px 'Calibri'";
}

VB.NET

Protected Sub Application_PreRequestHandlerExecute(ByVal sender As Object, ByVal e As EventArgs)
    ' ...
    DevExpress.Web.ASPxWebControl.GlobalThemeBaseColor = "Green"
    DevExpress.Web.ASPxWebControl.GlobalThemeFont = "30px 'Calibri'"
End Sub

If theme settings (base color or font) are defined both declaratively (in the web.config file) and programmatically, settings specified programmatically via static properties (GlobalThemeBaseColor and GlobalThemeFont) are applied.

Value Formats

The following formats are used when you specify values for a theme’s base color and font.

Base Color

Specify the color value in HTML format. The following formats will be parsed correctly:

RGB or RGBA colors

Note that for RGBA colors, the alpha parameter is not applied.
Examples: "rgb(255, 0, 0)", "rgba(0, 255, 0, 0.3)"

Hexadecimal colors

Six-digit (#rrggbb) and three-digit (#rgb) formats are allowed.
Examples: "#FFF000", "#FFF"

Color names

Note that color names are not case-sensitive.
Examples: "Red", "green"

Font

Use a value that sets all font properties in one declaration. Refer to the following section of the W3C website to learn more: Shorthand font property: the font property.

You can set the following font properties: font-style, font-variant, font-weight, font-size/line-height, font-family”

Values are required for font-size and font-family.

C#

DevExpress.Web.ASPxWebControl.GlobalThemeBaseColor = "#00FF00";
DevExpress.Web.ASPxWebControl.GlobalThemeFont = "14px 'Segoe UI', Helvetica, Geneva, sans-serif";

VB.NET

DevExpress.Web.ASPxWebControl.GlobalThemeBaseColor = "#00FF00"
DevExpress.Web.ASPxWebControl.GlobalThemeFont = "14px 'Segoe UI', Helvetica, Geneva, sans-serif"

Important

Font Value Validation Required

In contrast to the base color value (which is validated by DevExpress internal code), the font value is validated only if you select it from a list of predefined valid values. A custom font value should be validated manually to protect the application from potential malicious modifications.

Limitations

Base color and font values are only applied to a global theme, which is defined via static properties (ASPxWebControl.GlobalTheme - for Web Forms, DevExpressHelper.Theme - for MVC) or within the web.config option (theme). If a global theme is not defined, the specified base color and font settings are not in effect.

The table below lists themes that support base color and/or font parameters.

Supported Parameter	Theme Name
Base Color and Font Both base color and font can be changed.	iOS, Material, MaterialCompact, Metropolis, MetropolisBlue, Moderno, Mulberry, Office365, Office365Dark
Font Only font can be changed. The base color value is ignored.	Aqua, BlackGlass, DevEx, Glass, Office2003Blue, Office2003Olive, Office2003Silver, Office2010Black, Office2010Blue, Office2010Silver, PlasticBlue, RedWine, SoftOrange, Youthful

If you only need to change part of a font setting (e.g., font size) and leave other settings unchanged (default), use the theme’s default font value and modify its parts as required. Default theme settings are listed in the table below.

Theme Name	Default Value (case and whitespace are important)
Aqua, Black Glass, Glass, Office2003Blue, Office2003Olive, Office2003Silver PlasticBlue, RedWine, SoftOrange, Youthful	Font: “12px Tahoma, Geneva, sans-serif”
DevEx, Office2010Black, Office2010Blue, Office2010Silver	Font: “11px Verdana, Geneva, sans-serif”
iOS	Font:“14px ‘Segoe UI’, Helvetica, ‘Droid Sans’, Tahoma, Geneva, sans-serif” Base Color: “#007BF7”
Material	Font:“14px ‘Roboto Regular’, Helvetica, ‘Droid Sans’, Tahoma, Geneva, sans-serif” Base Color: “#009688”
MaterialCompact	Font:“14px ‘Roboto Regular’, Helvetica, ‘Droid Sans’, Tahoma, Geneva, sans-serif” Base Color: “#35B86B”
Metropolis	Font:“12px ‘Segoe UI’, Helvetica, ‘Droid Sans’, Tahoma, Geneva, sans-serif” Base Color: “#FF8800”
MetropolisBlue	Font:“12px ‘Segoe UI’, Helvetica, ‘Droid Sans’, Tahoma, Geneva, sans-serif” Base Color: “#0072C6”
Moderno	Font:“14px ‘Segoe UI’, ‘Helvetica Neue’, ‘Droid Sans’, Arial, Tahoma, Geneva, sans-serif” Base Color: “#1279C0”
Mulberry	Font:“14px ‘Segoe UI’, ‘Helvetica Neue’, ‘Droid Sans’, Arial, Tahoma, Geneva, sans-serif” Base Color: “#BF4E6A”
Office365, Office365Dark	Font:“14px ‘Segoe UI’, Helvetica, ‘Droid Sans’, Tahoma, Geneva, sans-serif” Base Color: “#F87C1D”

The code sample below demonstrates how to set the font size for the Aqua theme to 20px, specify the font value in the following manner.

C#

DevExpress.Web.ASPxWebControl.GlobalThemeFont = "20px Tahoma, Geneva, sans-serif";

VB.NET

DevExpress.Web.ASPxWebControl.GlobalThemeFont = "20px Tahoma, Geneva, sans-serif"

Note that you can set a theme’s base color and font when using custom theme assemblies, but not when applying a theme with the ASP.NET Mechanism.