Martin,
Wire color will not matter other than making it easier for you to troubleshoot. I wouldn't worry too much about it.
As a safety measure, I did use different colors for the high voltage lines (red) and ground (green).
WARNING!!! The high voltage created in these can kill. Please remember that when doing any probing and always wait for the voltages to bleed down before putting your body parts in there!
Be sure and use stranded wire of course.
Another picture that may help with your pin numbering is from the Decware site of the ZKIT-1 schematic.
The socket pin #s are on there and should line up with your board.
https://www.decware.com/newsite/ZKIT1schematicrev2011.pdfI posted a Youtube video of an amp assembly guide on another thread here that was extremely helpful to me.
Let me know if you can't find it.