After some hours of playing I had the idea that instead of making coloured floor you could make some differently coloured belts for different machines 
There are colours available in the paint tab so you can paint your belts all ready. Take another look.
hm okay I read my thread again and I think it came out wrong 
I meant that instead of only the green “original” belts you could, at the moment building them, select another colour, not after placing the green ones 
And splitting an existing belt should keep the original color!
I suggested that paint should be free in my idea thread, since they have no game function other than ‘pretty’. Feel free to cast your support for that there. Then what’s it matter whether it comes with that colour. That being said, it would be cool if we could toggle the colour as we place belts.