Sending variable data to another script, best way?

e.g.

I have 2 cubes, and 2 scripts (scriptA = collision script & scriptB = game manager), and 2 int variables (intRed & intBlue) in scriptB (game manager) to keep track of the number of times I hit each cube

scriptA determines whether I have hit one of the 2 cube (Red or Blue), and when I have hit one of the cubes I want to add +1 to its "int" variable in scriptB (intRed or intBlue)

I don't need help with scriptA, I just need the best way to send +1 to the integers in scriptB