Bugfix, minor: color the overview customview correctly When using a custom color (from the SYS2 menu, layout), the overview customview was the only one presented in the wrong color. While the fix for this is rather simple (in hindsight), it was a non trivial search trough rather obfuscated code. There is a specific function to set the text color index on this page, but this only worked for a single line text string, that has the color index byte as the very first character. The original author already recognized that this function "could be extended", but left this extension as an exercise to the reader. So, the coloring is fixed by extending the function, and actually using it for the overview customview. Signed-off-by: Jan Mulder <jlmulder@xs4all.nl>