How do I change Caution to red text?

I am writing a DITA document. I am trying to change the color of the Note element choice "caution" text from black, which is the default, to red. I've tried changing things in the commonelements.mod, but with no luck. I know you can do this. I am not a programmer, so it would be helpful to have it explained in a step-by-step manner.

Thanks

Robert