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