well, that's quite a lot. i suggest you to do the following: search the tag <colors>, there put the following line:
<color name="yell" color="#50ffff00" end="#000000" size="16" />
this line defines a color shortcut. the name of the shortcut is yell. the color is yellow and is defined with the html-code (#ffff00). additionally there's a transperency defined (50 before the ffff00). the font color is #000000 and the font size 16.
then you search in the code the fields where a color shortcut is used (the shortcut looks like this: color="shortcutname"). replace one (with the color yell) and then watch on the tv what has changed. some objects can also be recognized by the position mentioned in the skin-file (attention: eLabels are positioned relative to the "parent"-eWidget)
in the code you have several objects:
eventview: what you get after pressing the info button on the rc
eZapMainMenu: what you get after pressing the dream button on the rc
enigma_lcd_main: the lcd while you're watching tv
enigma_lcd_scart: the lcd when you're in the video mode (not the file mode)
enigma_lcd_standby: the lcd in the standby-mode
ezap_main: what you get after pressing the ok button on the rc
below the object level you have the eWidgets, they are like the container for the texts. furthermore, you have eLabels, they are like textfields.