OpenScad Help Centre

[curious aardvark]

colours are pretty pointless.

If you are designing a print for dual extrusion. You simply comment out the parts for the second colour when your render the commands for the first.
And vice versa.
I guess you could make them different colours - but I don't. I'm not a colour focused person.
I never know when friends have decorated or bought new stuff. It's not important to me so i don't generally take notice of it.

Transparency is potentially useful if you're designing mechanisms within a shell. Otherwise - again - just unnecessary window dressing.
haven't used it yet - or felt any need to.

When i start doing encapsulated hinges I'll probably play with transparency.
But for most models - you don't need it.

I know a lot of cad packages are colour focused. Architecture packages use different colours for different line types and thicknesses.
I suspect this is one - of many - reasons i don't get on with conventional cad packages :-)