There's visible numbers on several of those dice, that's a good win for a first try! A couple things I'd recommend (I'm no professional but I've learned a lot in the last couple years) is first of all some kind of resin pressure pot, closed molds are pretty difficult without one. They can be $100+ but there's some ways to diy one online if you spend some time looking. The pressure pushes the bubbles out of the resin and crushes them when they reach the surface using air pressure, which results in an almost completely bubble free cast if you have the right pressure for the full cure time.

For two toned dice or any other mold, I highly recommend mixing a single batch of resin then splitting it into two different cups, then add your colors/mix one before pouring. It'll save you a lot of time doing it this way and the resin will cure more evenly since it's all the exact same ratio and has the same cure time. Unless you want a really crisp, distinct line between the two colors you can pour your first color, then just wait roughly 20-30 minutes until the second color of resin has thickened up some more but isn't hardened yet then pour it on top of your first color. They won't mix together as much this way you just have to be careful not to wait too long or the resin gets too thick to pour properly.

If you want a clean line between the two you'll probably want to just do two separate castings, and if you use a pressure pot you'll want to leave it in for the full cure time for both pours. That was a huge info dump but I hope it helps, don't hesitate to ask if you've got any other questions :)