Why is Mercury red?
Mars is red, Mercury is acually biege or grey. Although Mercury is the closest planet to the sun, it is a dull color.
Traditional thermometers are filled with red-dyed alcohol while others are filled with mercury which appears silver in color. Mercury thermometers aren't safe. When a mercury thermometer breaks on the floor mercury is released. Mercury is very toxic and venomous. One sole drop can kill you or make you very sick. Alcohol is dyed red to add more visibility. Otherwise it'll be very hard to read the temperature due to the alcohol's transparency.