This add-on will allow you to use 6 Google default functions with the added functionality of selecting a color to associate with.
This currently contains 6 default functions that you can use in google spreadsheets (sum, average, count, counta, max and min). But with an added bonus! You can now not only choose the range of cells you want to use that function for, but you can now designate a color for it too.
Let's say I have a list of items. The list of items are sorted by color. I only want to get the sum of the items with a red color. You can now do that!
I've created a function builder which helps you get the color you want to use, the range you want to use and the type of function you would like. Once its built out it's just a paste into a cell and you're good to go!