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