Here’s a little tip some may find useful when trying to match colours to paint surfaces.
I have started using a little app called Color Picker which allows you to determine the colour of anything on your screen with an eyedropper. It classifies it in different ways, eg using the hex system. You can then copy the hex reference to your clipboard and paste it in the material selector in SU.
I expect someone will tell me you can already do this from within SU!
Color Picker can be downloaded here: https://itunes.apple.com/gb/app/color-picker/id641027709?mt=12