The sky is violet, but violet (in the UV region,
See also: What color is the sky?
The human eye is very sensitive to light in the middle of the so-called visible spectrum. We see yellows and greens, even when they are at very low intensities. But in the very deep red or at the violet end of the spectrum (near
So, while there really is more violet light scattering through the air particles in the sky, the blue color is seen more easily.