If your skins don't match, you can touch up the patterns with a little leather dye and a very small brush. I dilute the dye with alcohol and put on several thin coats until they match.
Here is an example, mis matched color in two copperhead skins, spliced and touched up with leather dye. There are actually three skins on this bow, all matched with a little wash of leather dye on the hour glass patterns. Takes a little practice to learn the technique but lets you use some pretty mismatched skins.
The pattern on the left side was dark, the right pattern had almost no color after I removed the scales, medium brown leather dye evened them up.
