White Blood Cells
neon is a colourless element
insects
Plasma I think.
red because horses blood is red
It will be colourless if there are no RBCs.
An ice fish
It is a tiny colourless disk found in the blood of the vertebrates that helps with clotting of the blood.
It's a colourless liquid organic compound.
Helium is a noble gas, it is colourless, odourless gas at STP. It is a chemically inert element.
White blood cells (leukocytes) are round and colorless, often accounting for less than 1% of the total blood volume. They play a vital role in the immune response by defending the body against infections and foreign invaders.
Diamond, graphite, and carbon black respectively - in other words, carbon.
Neon is a colourless gas except when an electric current passes through it, as in a neon sign.