Maybe Water, it’s blue on the outside but in the inside it’s clear. The better answer is what color is the air
Prokaryotes lack an organized nucleus and other membrane-bound organelles, the prokaryotic DNA is found in the central part of the cell called the nucleons, the cell size ranges from 0.1 to 5.0 in diameter, the cell wall of a prokaryote acts as an extra layer of protection, helps maintain cell shoe and prevents dehydration.
Their gametes would have half the number of chromsomes, so 24.
The primary muscle used for normal breathing would be the lungs. Addition muscles used would be the diaprahm.