We have the same problem quite often. A customer will want us to build a unit of some type to match an existing item with similar coloring. We will take a item of that color and some sample scraps of the mateial we used to a local paint dealer and have him/her mix tints to standard stain or paint to get the desired results. It takes some time, but if it produces a happy customer, then it's ok. By the way, go to a independant dealer, not one of the big box stores. This has allways given better results.