Hi
Open colors.xc with Notepad++ change the number after 0x
according to what new color you want, use this site:
http://www.w3schools.com/tags/ref_colorpicker.asp
Yes, sound is a bit hard. This is a bit old but should still be useful:
http://forum.worldoftanks.eu/index.php?/topic/17410-tutorial-how-to-make-your-own-tank-sounds-in-wot/