Well, as I understand it, the most sure fire way to get a bumblebee that really holds their color is to start with an incredible pastel gene that doesn't brown out as significantly as many do and to then combine it with a spider you really like. You've got a decent looking bee there, but it's not going to throw higher quality animals than the parent, you have to bring that super high quality(which a non-browning bee is) to the table through the parents. This is from personal research, not experience btw.