a cross color mixing platform, it outputs one space pipe with two inputs, you can squish it into a T platform (most likely), its 8 color mixers * 3 = 24 / 2 is 12 full pipes
It's all on one floor so its compatible with (as i said) one, two and three floors.
Space is wasted so i wouldnt be suprised if you could make it into a 2x1