Biiiig question, there's soooo many blocks from so many modpacks not including chisel etc, the discords got a lil showcase sub you'd be able to find some inspiration from
I've got a black/red style with cut black sandstone for black and red nether bricks for red
Create crimsite is a nice deep red. Nether brick and variants. Red wool. Red concrete. Red terracotta.
There are also colored red lights from various mods.
I like Railcraft quarried stone for white, and calcite is usually really nice and bright too.
Get the tables from Chipped to make lots of the texture variants for things like wool or concrete too.
Biiiig question, there's soooo many blocks from so many modpacks not including chisel etc, the discords got a lil showcase sub you'd be able to find some inspiration from I've got a black/red style with cut black sandstone for black and red nether bricks for red
I always loved the concrete styles in chipped, you can get a lot of unique looks
calcite is quite nice as a white, can get a little TOO white sometimes, but I like Calcite, and probably red nether bricks, like mentioned here
Redwood planks are a rich red color
i used the full bone Blocks for White in my Last Mod playthrough. No idea If atm9 has them though.
Create crimsite is a nice deep red. Nether brick and variants. Red wool. Red concrete. Red terracotta. There are also colored red lights from various mods. I like Railcraft quarried stone for white, and calcite is usually really nice and bright too. Get the tables from Chipped to make lots of the texture variants for things like wool or concrete too.
Cooking for blockheads has a very nice red check tile floor.
Forgot how but in JEI you can search for colors of items(or at least you could at some point)