Hard to read texts on the AboutDialog when a dark desktop theme is selected #897

Description

AboutDialog's background colors are hard-coded with an assumption that the text is rendered with a dark color, which is, however, not true when a dark desktop theme is selected.

Steps to reproduce

Steps to reproduce the behavior:

1. Build and install Mozc
2. "%ProgramFiles(x86)%\Mozc\mozc_tool.exe" --mode=about_dialog

Expected behavior

You can clearly see the contents on the about dialog.

Actual behavior

You can clearly see the contents on the about dialog.

Screenshots

On Windows 11 23H2

On macOS 14.4

Version or commit-id

ce08bae

Environment

• OS: Windows 11 23H2
• OS: macOS 14.4