Here is the full list of all 46 Color Guardians achievements.
Collect 100 big color orbs.
Complete 5 bonus color sequences.
Clear a level with no stars.
Get 3 stars on any level.
Defeat the Castle Boss.
Grab 2000 color orbs.
Change colors 215 times on a level.
Get diamond stars on any level.
Grab 500 orbs the perfect way.
Find all of the Castle's hidden Tokis.
Defeat the Windmill Boss.
Stay 5 minutes on a level using Jellies wihout dying.
Use windchopper for the first time.
Fall into the water 3 times in a row.
Fall into a pit with the chopper.
Get to the choppa!!! Don't miss any of the choppers on Windmill Level 6.
Clear Crystal Cave level 6 without crashing any obstacles on the color rails.
Clear a level collecting only multicolor orbs.
Almost perfect a level and miss by one orb.
Die 500 times.
Defeat Krogma on Crystal cave.
Complete a level without grabbing a single orb.
Encounter the Old Goblin.
Defeat the Mountain Boss.
Clear the final Krogma level without dying.
View the whole world with color for the first time.
Clear a level with all characters.
Clear a boss level without dying.
Clear a speed level wihout dying or missing any orbs.
Clear Crystal Cave level 3 without grabbing any orbs.
Clear a level without passing through checkpoints.
Clear the credits level collecting all orbs.
Release all Tokis from their cages.
Clear a level playing with the secret character.
Clear final Krogma level with all 3 characters.
Clear a Boss level using the secret character.
Clear at least one extra level collecting all orbs.
Earn a bunch of stars. (20%)
Earn a big pile of stars. (30%)
Earn an incredible amount of stars. (50%)
Fall off a cliff 100 times.
Get to the end of windmill 7 level without using a single jelly.
Open all gates in Mountain level 2.
Destroy every single goblin in Mountain level 3.
Clear Mountain level 6 without grabbing any orbs.
Win all achievements in the game!