Coated strings vary quite a bit in my experience. Elixirs have it figured out on how to get decent brightness out of a coated string that does stay bright much longer than uncoated strings. I bought a set of DR's in orange to go with some gold trim on a T-bird. They looked good, but sounded like six month old heavily played rounds they day I put them on the bass. That wasn't what I expected for the price. I tried a set of D'Adderio's coated string (EXL's) and they sounded great, but I didn't get anywhere near the life out of them as I do Elixers.
I have some Ernie Ball Cobalt flats that are a couple years old that I've moved from one bass to another for at least four basses, and they still sound great. They are starting to get fret wear spots in a few places. They aren't coated, and they aren't as bright as rounds, but they are bright for flats, a lot brighter than dead rounds, and stay about the same for a long time. I'll be buying another set or two. Swapping the set I have between basses was to see if they sound good on different basses. They do, and were most impressive on my jazz parts bass.