Geometrical optics can describe how light rays reflect and refract without explaining what light physically is. Maxwell's theory supplies that deeper identification: light is electromagnetic radiation.

Visible light occupies only a small frequency range within the electromagnetic spectrum.

Connecting the descriptions

In the electromagnetic picture, light consists of oscillating electric and magnetic fields propagating through space.

In the wave picture, wavelength, phase, interference and diffraction describe how those fields propagate and superpose.

In the ray picture, the same wave propagation is approximated by rays normal to wavefronts when the relevant structures are much larger than the wavelength.

Vacuum speed

All electromagnetic radiation propagates in vacuum at

$$c=\frac1{\sqrt{\mu_0\varepsilon_0}}.$$

Visible colors correspond to different frequencies and wavelengths within the visible range, not to different underlying kinds of wave.

Why several models remain useful

Calling light electromagnetic does not make ray optics obsolete. Different descriptions expose different scales and questions: rays are efficient for imaging, wave optics is necessary for interference and diffraction, and Maxwell's equations explain the fields themselves.

The models are therefore complementary descriptions of the same physical phenomenon.