OK, so we have just put up new bat-n-board rough sawn sinding. My wife thought she had the coloring all figured out and even tested on small test scrap pieces. However, when she began painting the house, it seemed too be way darker, but she continued on thinking it would lighten as it dried. Well it didn't. The back wall of our house is now a very dark chocolate brown. What she wanted is something about 1-1/2 to 2 shades lighter. Does anyone know if there is a way to lighten a colored stain? It's Behr Premium Semi-Transparent Weatherproofing - Deck, Fence & Siding Stain - No. 5-77 Tint Base with coloring.

Any help would be greatly appreciated!!!