Black locust is green/yellow to sort of tan-can get fairly dark tan/brown. Honey locust is pale pink orange to strongly salmon pink/orange, often with rust colors throughout. The color is very stable and does not change much if at all as it ages. Both are very nice woods, honey locust is one of my favorites and I have just turned two pieces. Very stable wood from green to dry which makes it very suitable for green turning. I'll post some photos.
John