Question: What makes cells and neurons coloured and what colours are they?

Callum Johnston answered on 23 Nov 2012:

Most cells arent very colourful. When you look at a fresh brain it is a pinky-red colour, but that is caused by all the blood in it. Once the blood has been removed the areas of the brain that have lots of neurons are grey and the areas that have lots of glia cells are white, this white colour is caused by a substance called myelin, it wraps around neurons like the rubber coating on a metal wire, and is mostly made of fat which is why its white.

However, scientists can die cells different colours so they can tell which ones they are looking at under a microscope. This is done by making the die stick to proteins which are only present in the certain cells types. You can see a picture on my profile of some neurons stained green and some myelin stained red!