The problem is that no one offers a maroon reflective material. It has to be printed on a printable base that absorbs the ink. That has to be done on large injet with special UV resistant inks. You can sometimes see streaks in the decals out there where the inks didn't absorb evenly.
I believe most of the sign companies will send you a small sample. That is what ended up happening with my reflective trunk decal. After I had already installed mine (on a burgundy car) and it reflected purple, it looked so bad I took it back off. I called the company and they explained the issue with the new printable 3M reflective material. They sent me a sample of the old 3M material that had been discontinued that once printed, reflected properly (a nice dark red), then of course, the new stuff that looks maroon in the daylight, but reflects purple at night (tacky looking). They also sent me a sample of the ruby red material which is really just a slightly dark red (too red for my burgundy car). Now I see they actually offer this stripe from Avery- a burgundy (not the correct shade of maroon) that reflects the right color.