Linux's Gnome defines themes that set the color scheme and style for window frames, buttons, scrollbars, and other components drawn by Gnome's GTK user interface toolkit. For Java applications, changing the theme should set colors in Java's java.awt.SystemColor objects, which applications may use to customize their user interfaces to match the current theme. Unfortunately, there are some problems here.
This article discusses SystemColor problems with Gnome, and provides color swatches, RGB/HSV values, and downloadable color lists for the default SystemColors on Linux.
Table of Contents
This article is part of a series on How to use SystemColors to access OS user interface theme colors that catalogs Java's SystemColors for user interface themes in major OSes. The color catalogs provide a resource for comparing theme colors and creating custom Java components that match the themes.
Accessing Gnome theme colors from Java
A Gnome theme defines the color scheme and style for window frames, buttons, and the like. Each Linux distribution comes with a starter set of themes and sometimes a branded theme for the distribution, such as the orange Ambiance theme for Ubuntu, or the light blue Fedora theme for Fedora. Additional themes can be downloaded from Gnome.org, including many that mimic the appearance of Mac, Windows, and KDE themes.
Java's java.awt.SystemColor class provides access to well-defined theme colors, such as the foreground and background colors for buttons, text fields, and menus. Each theme color has a static SystemColor object. For instance, SystemColor.textHighlight is the background color for selected text in a text field.
A list of SystemColor objects and their use is discussed further in the lead series article. The following article discusses Gnome-specific issues and provides color swatches and RGB values for the default SystemColors.
Selecting Gnome themes
Briefly, Gnome themes are selected using the Theme tab of the Appearance Preferences pane. Each theme combines settings for the color scheme, button style, window frame style, and (optionally) the fonts used. The theme used for these screenshots is Ubuntu's default Ambiance theme.
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| Figure 1. Theme selections in the Gnome Theme tab of the Appearance Preferences pane. |
For any theme, clicking on the Customize button on the preference pane shows the Customize Theme control panel with tabs to adjust the button style, color scheme, window style, icon set, and mouse pointers:
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| Figure 2. Controls, Colors, and Window Borders in the Linux Gnome Customize Theme control panel. |
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Dealing with Gnome SystemColor problems
Java's SystemColor class is a flawed approach to accessing OS theme settings. While colors are defined for button backgrounds and text, none are defined for tabs, checkboxes, radio buttons, progress bars, and more. Though a highlight color is defined for selected text, none are defined for selected menu items, toggle buttons, radio buttons, or checkboxes. Beyond colors, Java has no access to OS theme fonts, button styles, window title bar buttons, and so forth. So, while there are specific problems on Linux (and every OS), the primary problem is that Java's theme access is flawed.
Java's user interface class libraries (java.awt and javax.swing) are implemented by Linux Java distributions such as Oracle's JDK, Oracle's JRocket, IBM's JDK, and the open source OpenJDK and Apache Harmony. On Linux, all of these are built atop the GTK+ user interface toolkit used by Gnome itself.
However... none of these Java distributions initialize the SystemColors to match the Gnome theme. The SystemColor feature is simply broken on Gnome. This is a known bug, but it has gone unfixed for years.
Instead, on Linux the SystemColors are initialized to generic defaults that have nothing to do with the current Gnome theme, and they don't change when the Gnome theme is changed. Worse, the generic defaults depend upon the Java distribution in use. Oracle's JDK, Oracle's JRocket, IBM's JDK, and the OpenJDK all initialize the colors one way. Apache's Harmony initializes them another way.
Fortunately, there is a work-around. On Linux, the UIDefaults for the native "GTK+" look and feel are set to the proper Gnome theme values, and they update as the theme is changed. These look and feel defaults can be accessed whether or not the Java application uses the look and feel.
Color swatches and values
While the bugs in the SystemColor implementation insure that the class has almost no use on Linux, the color swatches below nevertheless show the initialized (wrong) defaults for several Java distributions.
Oracle JDK, Oracle JRocket, OpenJDK, and IBM JDK
Oracle's JDK is the gold standard for Java implementations. OpenJDK is nearly the same, with Oracle's proprietary code removed. Oracle's older JRocket and IBM's JDK track these closely and initialize the SystemColors identically (and incorrectly).
| Name | Hex triplet | Red | Green | Blue | Hue | Satur. | Value |
|---|---|---|---|---|---|---|---|
| activeCaption | #000080 | 0 | 0 | 128 | 240 | 100 | 50 |
| activeCaptionBorder | #c0c0c0 | 192 | 192 | 192 | 0 | 0 | 75 |
| activeCaptionText | #000000 | 0 | 0 | 0 | 0 | 0 | 0 |
| control | #dfdfdf | 223 | 223 | 223 | 0 | 0 | 87 |
| controlDkShadow | #4a4a4a | 74 | 74 | 74 | 0 | 0 | 29 |
| controlHighlight | #e6e6e6 | 230 | 230 | 230 | 0 | 0 | 90 |
| controlLtHighlight | #ffffff | 255 | 255 | 255 | 0 | 0 | 100 |
| controlShadow | #6b6b6b | 107 | 107 | 107 | 0 | 0 | 41 |
| controlText | #000000 | 0 | 0 | 0 | 0 | 0 | 0 |
| desktop | #005c5c | 0 | 92 | 92 | 180 | 100 | 36 |
| inactiveCaption | #808080 | 128 | 128 | 128 | 0 | 0 | 50 |
| inactiveCaptionBorder | #c0c0c0 | 192 | 192 | 192 | 0 | 0 | 75 |
| inactiveCaptionText | #000000 | 0 | 0 | 0 | 0 | 0 | 0 |
| info | #e0e000 | 224 | 224 | 0 | 60 | 100 | 87 |
| infoText | #000000 | 0 | 0 | 0 | 0 | 0 | 0 |
| menu | #c4c4c4 | 196 | 196 | 196 | 0 | 0 | 76 |
| menuText | #000000 | 0 | 0 | 0 | 0 | 0 | 0 |
| scrollbar | #c4c4c4 | 196 | 196 | 196 | 0 | 0 | 76 |
| text | #ffffff | 255 | 255 | 255 | 0 | 0 | 100 |
| textHighlight | #000000 | 0 | 0 | 0 | 0 | 0 | 0 |
| textHighlightText | #c4c4c4 | 196 | 196 | 196 | 0 | 0 | 76 |
| textInactiveText | #808080 | 128 | 128 | 128 | 0 | 0 | 50 |
| textText | #000000 | 0 | 0 | 0 | 0 | 0 | 0 |
| window | #dfdfdf | 223 | 223 | 223 | 0 | 0 | 87 |
| windowBorder | #c4c4c4 | 196 | 196 | 196 | 0 | 0 | 76 |
| windowText | #000000 | 0 | 0 | 0 | 0 | 0 | 0 |
Apache Harmony
Apache's Harmony is an independent full implementation of Java. While it uses different and more esthetically appealing SystemColor defaults, its defaults are still wrong and don't track the OS theme.
| Name | Hex triplet | Red | Green | Blue | Hue | Satur. | Value |
|---|---|---|---|---|---|---|---|
| activeCaption | #336699 | 51 | 102 | 153 | 209 | 66 | 60 |
| activeCaptionBorder | #cccccc | 204 | 204 | 204 | 0 | 0 | 80 |
| activeCaptionText | #ffffff | 255 | 255 | 255 | 0 | 0 | 100 |
| control | #dddddd | 221 | 221 | 221 | 0 | 0 | 86 |
| controlDkShadow | #777777 | 119 | 119 | 119 | 0 | 0 | 46 |
| controlHighlight | #eeeeee | 238 | 238 | 238 | 0 | 0 | 93 |
| controlLtHighlight | #ffffff | 255 | 255 | 255 | 0 | 0 | 100 |
| controlShadow | #999999 | 153 | 153 | 153 | 0 | 0 | 60 |
| controlText | #000000 | 0 | 0 | 0 | 0 | 0 | 0 |
| desktop | #224466 | 34 | 68 | 102 | 210 | 66 | 40 |
| inactiveCaption | #888888 | 136 | 136 | 136 | 0 | 0 | 53 |
| inactiveCaptionBorder | #cccccc | 204 | 204 | 204 | 0 | 0 | 80 |
| inactiveCaptionText | #dddddd | 221 | 221 | 221 | 0 | 0 | 86 |
| info | #eeeeee | 238 | 238 | 238 | 0 | 0 | 93 |
| infoText | #222222 | 34 | 34 | 34 | 0 | 0 | 13 |
| menu | #dddddd | 221 | 221 | 221 | 0 | 0 | 86 |
| menuText | #000000 | 0 | 0 | 0 | 0 | 0 | 0 |
| scrollbar | #cccccc | 204 | 204 | 204 | 0 | 0 | 80 |
| text | #ffffff | 255 | 255 | 255 | 0 | 0 | 100 |
| textHighlight | #336699 | 51 | 102 | 153 | 209 | 66 | 60 |
| textHighlightText | #ffffff | 255 | 255 | 255 | 0 | 0 | 100 |
| textInactiveText | #dddddd | 221 | 221 | 221 | 0 | 0 | 86 |
| textText | #000000 | 0 | 0 | 0 | 0 | 0 | 0 |
| window | #ffffff | 255 | 255 | 255 | 0 | 0 | 100 |
| windowBorder | #000000 | 0 | 0 | 0 | 0 | 0 | 0 |
| windowText | #000000 | 0 | 0 | 0 | 0 | 0 | 0 |
Downloads
Each Java implementation's default SystemColor set is available as a download in the X11 rgb.txt file format:
- Oracle JDK, Oracle JRocket, OpenJDK, and IBM JDK:
- Apache Harmony:
Further reading
Related articles at NadeauSoftware.com
- Java tip: How to use SystemColors to access OS user interface theme colors is the lead article for this series on
SystemColoruse for the major OSes. - Java tip: SystemColors for Linux KDE user interface themes discusses accessing theme colors on Linux systems using the KDE user interface.
Web articles
- Color-Name Dictionaries. Aubrey Jaffer's article goes into great depth on different standard color name lists and includes X11 rgb.txt format files for many of them.
- X11 color names. Wikipedia's article discusses the standard X11 window system "rgb.txt" colors that form the basis of the W3C's list of standard colors for HTML and CSS. The article lists the color names and RGB and HSV colors. The X11 rgb.txt file is available for download from XFree86's CVS archive.
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