What are Stars and Bolts next to a player's name? And what do the colors mean?

It's simple - you can earn these by playing the game and meeting these requirements:

Yellow Star - Reach Level 99 on your current Hero.

Red Star - Get to Decode Rank 99 (DR99) on your current Hero.

Yellow Bolt - Reach God Tier (GT) on your current Hero.

Red Bolt - Reach God Tier and get to Decode Rank 99 on your current Hero.