There's a "tool" out there, can't remember what it's called but it's a piece of red plastic, you look through it and you can "see" the true lightness and darkness. At least that's what I've been told.

What's weird - when using the red one - all the reds - no matter how dark - look light

I wonder if those old 3D glasses would work, you know the only cardboard ones??? Remember those?

That's where I got the idea from... It's called a 'value finder'.. I think,you can pick them up at JoAnns, LQS, Micheals.. it certainly is prettier looking than what I use, but... I am cheap, cheap.

I have a red one - been looking for a green one -

Good Job :)