Do I salute to colors if I’m still iN uniform but off post ?

Why not, to you have to be in public to do the right thing? You are in uniform, that mean you are suppose to face the colors/music and render the salute until it is done.

Follow what you've been taught. Helps if you pull off the road first.

If you are off post and you are referring to colors playing from post then no you do not.