Yellowjacket females are really just now hitting prime production years (3+ calves out of one). So nobody really knows what consistently works.
The Texas Twister x Yellowjacket combination hit a home run on probably the one cow it was tried on last year for Kris Black. In addition to the three calves being very high sellers, one placed at Fort Worth, another was second or third in a very tough Charolais class at San Antonio, and I think the third one was Champion Simi at San Antonio. I bet a bunch of YJs got bred to him last fall.
I have one really good YJ female, but Troubador did not work real well on her first calf. Calf was very, very stout in the end, but was impossible to get fat enough to win down here at our majors.
I'm breeding mine Monopoly next fall. If you get a black one, chances are it will be a real good one if your cow is good. If you get color, even better.
If you want a colored bull, I'd probably go either Texas Twister or Man Amongst Boys. The MAB is just a guess, but I bet he'd soften one. I do not think most Charolais or Charolais-x bulls will soften up a YJ enough. She'll give you all the muscle you need, you just need the pretty and softness somewhere from the Heat Wave line.