Question

which light causes the greatest refraction out of red, blue and white, and why?

Answer 1

red light has the highest wavelength. refraction depends on refractive angle. and refractive angle depends on speed of light.
More the wavelength, more speed.(Velocity=frequency*wavelength)
More the wavelength, more refractive angle. So, red light causes the greatest refraction.
It is not white light, because it's wavelength is average of all the wavelengths in visible light, which is less than that of red light.

Answer 2

isn't it the less wavelength, more refraction?

Answer 3

Yeah, you are right. It was my fault. I checked my book.
The equation is 'm=m0+(A/wavelenth^2)'. Where m and m0 stands for refractive angle in a medium and refractive angle in air.
In that case, blue light has the highest refraction.

Answer 4

m and m0 are refracive indices.