GN Green

Hello.
I am trying to touch up on a SD-9 made by Life Like Proto 2000, and every green I tried is a shade off. What can I do?
Jay[V]

What color green have you been using. Officially it is Pullman Green (Assuming it is a loco done in Orange and Green) If it is a shade light, try adding a little black, if it is a shade dark, add a little white.