I had a green OBS F-150 that I did purple under the dash in the front and under the rear of the front seats in the back so it would shine out onto the floor. The purple looked good with the green. I also did the "chicken lights" in the upper corners of the windshield shining out the front. I liked it. Interestingly I later saw other purple colored lights that were being sold at a truck stop for that location and they were sold as anti-glare lights.
Then I did amber in my black '02 F-150 and munted them under the the front on the seats and also behid the grille out of direct sight for an ambient glow in the front. Sorry I don't have pictures of either set-up. Wish I did though.
I may try the blue LED's in this truck. Would look good with the grey interior.