Another trick we professional photographers use, is to carry around an 18% Grey Card.
You take one picture of it under the lighting you are going to be using before you take any of your intended subject, then continue your photography.
If you use color negative film and get it processed at a lab, you just tell them that you have an 18% Grey Card on the first frame and they will then color balance their machine to that, and all the images should come out close to intended color.
If you use a digital camera, balance the color to as close to the 18% grey Card as you can in your software and again, the rest of the images, should only require minor tweaking.
You didn't mention which software package you are using, but if you want to get into more precise handling of your images, then you have to bite the bullet and get Photoshop, if you don't already have it.
"Forget the rest, gotta have the best."
I have tried many packages over the years, nothing compares, except for the cut down version, Photoshop Elements.
My 2 F stops worth.
PS Check your Email.