Tried to p.m you but your box was full mate. I'll try again.
...Nope. still full.
Basically not sure about the colour stickers.
I'll see if I can find out. They are nothing to do with the actual building process as they are only used on completed cars awaiting transportation indicating that they serve a holding/shipping purpose.
If I find out more I'll let you know.
As for vin lettering, I saw your thread briefly, and that question was answered correctly by BruceK or Basil I believe.
All the best.