I have been trying for two days to get a color that I can paint on cake and that can be seen that looks like a light tan color. It's bad enough my store is out of gum paste so I have been working with fondant. Then the first day I had a cake melt down. It was breaking and falling apart so finally I froze it to get the thing to stand up. Ahh. Now this letter paint is driving me nuts. What was I thinking.....lol.
If you have some brown icing paste, you could add some of the wilton white-white,and that would make it a liquid and would lighten your shade of brown also. Hope this is helpful.