Couple things: 1) This has been a WIP in my Sims projects folder for ages, 2) I feel like as soon as I post this someone will say "Oh, so-and-so already converted that a long time ago", 3) I really searched hard to find these for TS3 and only found expansions of the TS2 single wall and 4) this might be the one decorative item that I miss most from TS2.
With all that rambling, here you go. BUT, here's some more...um, couple things: 5) Don't drag the color slider to absolute Black (the texture will pretty much disappear), 6) Don't drag the color slider to absolute White (the walls will be eye bleedingly too bright), and 7) I would suggest using the pre-made swatches in CAS for your color selections.
In the Wall-Tile catalog.
Costs 8 bucks.
Re-colorable, of course.
[DOWNLOAD] Hipster Mosaic Walls.
[DOWNLOAD] Hipster Mosaic Floors.
EDIT: I'm dumb...why didn't I make floors? I DUNNO. Anyway. Floors added. Wish I could track down the 8 people who already downloaded. Poop.