Rancy,
are you after a red hue, or a green hue?
pretty much start with white,, add a small amount of red and green, like drops, watch as it shifts. a few drops either way will sway it from the red hue to the green and back.
One thing to really watch out for on cream, It tends to shift color quite drastically as it dries , then again when you clear it.
If you are using copper or orange trim then you may want to keep it to the reddish side.
I try to avoid using much or any black in lighter colors like this, unless you are trying to dirty it up some.