This is Brush-Up! Brush-Up aims to improve and brush up many textures that felt either a bit outdated, or just a little out of line.

Modrinth Page

Changes

Brush has been tweaked
All dye items (tweaked and retextured both to better help differentiate & to better match their dyed-block colours)
Azalea, Dripleaves, & Spore Blossom have unique item textures
Blaze Rod & Powder have been updated
Enchanted Golden Apple (now called Enchanted Apples) uses its own item texture
Glass Bottle, Potions, and Experience Bottle have been tweaked
Music Discs have been updated
Bowls, Buckets, & Flower Pot have been tweaked
Nether Wart Item has been retextured
Pink Petals' item has been retextured
Spyglass (Handheld position now matches Bedrock Edition)

All coloured blocks (concrete, concrete powder, terracotta, glazed terracotta, wool)
Banners have been tweaked
All Stripped Logs have been retextured
Chests have been retextured
Sea Lantern has been retextured
Fire, Lava, & Magma have been updated
Nether Portal (including respawn anchor top texture) has been updated
Water has been tweaked
Torches have been updated
Beacon has been remodelled and retextured
Cherry Door, Trapdoor, Leaves, Sapling have been tweaked
The models for pink petals has been tweaked
All Dirt blocks have been updated
Grass's top texture has been tweaked
Infested Stones have slightly different textures
Decorated Pot has been tweaked
Flower pot has been updated
Sculk, Sculk Sensor, Sculk Shrieker have been tweaked
Moss has been tweaked
Spore Blossom has been retextured
Chorus Plant & Flowers have been remodelled & retextured
Dragon Egg has been updated with a remodel & retexture

The "darker" palettes of armour trims have been tweaked so that the lighter colours aren't just brightness-lowered versions of their originals
The water breathing and darkness effect icons have been tweaked
The spyglass scope texture has been tweaked

Further changes may be found in the changelogs of the respective versions :)