Among red and violet color which has higher speed?

All the transverse electromagnetic waves in vacuum have the same speed of ##~~3 * 10^(8) "m/s"##.

It's the frequency and wavelength that differs.

Red light has a lower frequency (longer wavelength), while violet light has a higher frequency (shorter wavelength).

In other media the speed differs. That's why we have not only refraction (bending of light), but also dispersion, like in a prism. Red light entering glass is broken less than violet light. The amount of refraction depends on the relative speeds in the two media (vacuum and glass). We call that the breaking index ##n##, where ##n=##speed in vacuum/speed in glass. Apparently the ratio for red is less than that for violet. ##n_"red"< n_"violet"##

In other words: The speed of light in any other medium than vacuum is higher for red than for violet.