This used to be one of my fav tools
Curves is located in the tools.
it helps for making shadows also if it's a solid color
step 1 - open a cover or edit
step 2 - go to curves
step 3 - at first when it opens, you'll like a graph and a line going through.
step 4- that's to make it dark or bright
step 5- if you want it bright move the line up, for dark move it down.
step 6-there are other things you can do, if you click on the circle, 3 other colors will pop up. red,blue, and green.
step 7- you can mess with these to even out the colors on your cover.
This is a chapter to make-up for all the days or week I've been gone. I'm so sorry