Here is the full list of all 33 Chicory: A Colorful Tale achievements.
Collect all decor
Complete all art classes
Reveal 100% of the map
Discover all Brush Styles
Collect all clothing items
Solve all of Oats' outfit riddles
Fill in Gelato's photo gallery
Pick up all litter
Destroyed the Brush.
Grew a brush
Sang with Chicory
Solve the mystery of stolen furniture
Delivered all of Artichoke's mail
Find all lost kids
Deliver mail for Artichoke
Shook Chicory's hand
Painted your wielder self-portrait
Collect 50% of decor
Planted the Brushflowers
Pick up 50% of litter
Collect 50% of clothing items
Started the Wielder Trials
Met Queen Drosera
Pick up 25% of litter
Reveal 50% of the map
Collect 25% of decor
Discover 50% of Brush Styles
Collect 25% of clothing items
Chicory painted you
Had a conversation with Chicory on the phone!
Met Chicory!
Return Beans' kids to her
Pick up Chicory's brush