overlay is usually more saturated than color layer, and will change the values slightly too. ^^ you can really see the difference if you fill the whole canvas with a really really bright color and switch between color and overlay.
it should be in the same place under the layers box as shown in the pic. just to the left of the opacity. click on it. I use pse7 and that works for me it should be toward the bottom. the bottom 4 options are Hue, Saturation, Color and Luminosity if that helps you find it
Yes, I have those, but what I haven't found is how to manipulate those (such as how you chose a color for your color layer, etc.) Seeing as I have a color option, there must be a way, but it's cleverly hidden if it's there. I've Googled it, but all I find is for Photoshop on Apple computers. Oh well. Maybe someday I'll figure it out. Thanks for replying!
I always loved the ability to work in layers because I could edit something without affecting everything else (e.g. correcting my shading or choice of color without screwing up the lineart), now I've got another reason to love them.