The red colour deviates the least and the violet colour deviates the most.

Which colour is deviated the least?

Also, the violet color has the least wavelength. Therefore when it travels from one medium to another, then it has the maximum value of the angle of incidence and the violet color will deviate the most. But the red color has maximum wavelength so it will deviate the least.

Which colour deviates the most and which colour deviates the least?

when the white light falls on the prism, every colour is refracted by a different angle. and violet deviates the most and red deviates the least.