they do not, the sky is a blue color because that is the color of light that breaks through the atmosphere. if air molecules did make the sky appear blue, then how would you explain a sunset?
purpleish
red
Blue White
they appear blue due to the flame
green
Red, or possibly green if the dress were dark blue.
Everything obsorbs or bounces light off of itself. There are also many wavelengths and different types of light around us. This blue object obsorbs each and every color except the blue you are seeing. The blue light reflects off of the object, thus making it appear blue to your eyes.
will appear black
Blue is a primary color, no two other colors can be mixed to make blue.
You can add the color blue to make purple more blue.
Blue is blue because things that are blue actually repel the frequency of light from the sun that would appear blue. Because that is the only color light that is reflected, that is the only color that we see. Things that are blue are actually every color BUT blue!