Roulette is the game today. Themed answers feature the words "black," "red," "even," and "odd," and the word "roulette" runs around the center square. Nice enough. The theme answers even give the impression of a clockwise spin, which is, I'm guessing, the direction of spin on a roulette table. So the theme is fine. Not too intrusive, and well executed.
1A: Genesis brother (ABEL) is uninspired (C-), but the rest of the top of the grid is pretty good. BLACKGOLD (17A: *Oil, informally) brings to mind the Beverly Hillbillies, which is always a good thing, and the chunky NE corner contains the equally nostalgic MIXTAPE (11D: Personal music compilation). The equally chunky SW is maybe the shakiest spot, with ANIN atop SANA and TINIEST (41D: Like the pinky compared to the other fingers) running through them. Doesn't "tiniest" imply that all the fingers are tiny to begin with? And maybe they are, compared to a Giant Sequoia, but compared to one another, they're all pretty much the same. "Smallest," sure, but "TINIEST?" Hmph.
I like STRETCH (23D: Warm up before exercising) and OPULENT (25D: Lavish), but TIO, TOA, ETTE, ECON, and TIPI (30A: Home on the range: Var.) is a pretty high price to pay. I guess the compromise really starts with the roulette wheel in the center, but geez, THATS a lot of LEAD dragging this grid down.
It's kind of a split decision. The chunky corners are nice, but the middle is tortured. I don't know, let's just call it a wash. A slightly dirty wash.