You need to download the whole Res folder from your N900 and point SygicColors to that folder on your file system. (Have a backup copy of the folder before making any changes.) I did not try to change icons, just colors and fonts. I was even able to add new fonts (just move ttf files into the fonts folder). Changes occur mainly in the skin folder, only changed files must be copied back to the N900. For editing: You simply have to try and test. The names of the colors etc. give a hint, what they are for. The tab "Application" is used while there has not been a GPS fix yet and for menu browsing, tab "Navigation" is used during turn-by-turn navigation etc., tab "Browse" probably when you browse the map (have not tested this). Changing colors: Mark the name of the color and click (or double click?) on the white field between color and font names. Changing fonts: Mark the name of the font and click on the button [...], mark the new font and click the [Change ...] button (cannot remember what exactly it is called). By the way: There is no indication of the source of the software. The website mentioned inside SygicColors is off. You must put a lot of trust on this, that it does not do any harm. I had it running in a Virtual Machine only, that was reset after use.