Add clay.. lighter than gravel, but it might look too similar
Clay contrast lowered, looks less harsh than gravel now
Add furnace, dispenser, dropper textures based on stone
Add crafting table, based on oak plank texture
Add command block, oak plank bordered with 'sudo'
Add bookshelf with 14 tan leaning books
My bookshelf looks more like a note block; make it one instead
A more colorful bookshelf, with red/green/blue alternating books
Add mossy cobblestone / moss stone, like cobble but with vines overlaid
Add plants: dandelion, rose, fern, deadbush - all same shape, different colors
Vertical dispenser and dropper fronts: rectangle and circle
Add farmland, wet/dry: same colors as dirt, but in stripes because it is more organized
Add snow, pure white
Add lilypad: green pentagon
Add monster spawner: like glass, but with a crosswise gridline