What are the individual Color Ids?

From what I could find so far, a list of IDs can be found on this Reddit post, although one of them appears to be unknown at this point:

There are 18 changeable colors right now.

• 0: Smasher/Dominator/Auto Smasher/Spike/Landmine base
• 1: Turrets/barrels
• 2: You (FFA)
• 3: Blue team
• 4: Red team
• 5: Purple team
• 6: Green team
• 7: Shiny Shapes (Green)
• 8: Squares
• 9: Triangles
• 10: Pentagons
• 11: Crashers
• 12: Neutral Dominators and Arena Closers
• 13: Leaderboard (FFA)
• 14: Maze walls
• 15: Others (FFA)
• 16: Controlled/Necromancer squares (FFA)
• 17: Fallen team (Fallen Booster and Fallen Overlord)
• 18: ???

All team colors including Others and You from FFA include bullets and bases as well.

Color ID 18 does not change anything that is displayed, as explained by a comment on the post:

18 doesn't do anything since it's default value is 000021 (which isn't a diep.io color).