I want to build a castle. I want it...

I want to build a castle. I want it to have many big towers and be approximately 80 blocks wide x 50 blocks deep. It should also use a gradient going up the length of the building. The lower layers should use deepslate, then andesite, then diorite, then calcite as the top level. For the roof I want half to use blue blocks and the other half to use red blocks.