Blue is the normal colour of the spiritual planes. If the blue lights were of different shades, it might mean the overhead planes,overmind, Intuition, Illumined Mind, Higher Mind. The blue colour can be the Krishna consciousness; there are different Krishna lights pale diamond blue, lavender blue, deep blue etc. It depends on the plane which it manifests...

All blue is not Krishna's light...

Diamond blue, Krishna's light in the overmind, lavender blue in intuitive mind. Blue is also the Radha's colour. A deeper blue is of the Higher Mind, the nearest of the planes between human mind and the supermind.

The Blue Light coming below the level of the Muladhara means that it has entered into the physical (physical-mental, physical-vital, material) consciousness. The two main obstacles here are the mechanical mind with its memories and desires of the past and the most outward sex-movements; these have to be overcome (especially the mechanical mind, for the other may be easily overcome if not supported by the vital proper) for the Light to possess all the physical consciousness. It is probably why it rose so strongly when the Light came to these parts.

Thence gazing with an immeasurable outlook
One with self's inlook into its own pure vasts,
He saw the splendour of the spirit's realms,
The greatness and wonder of its boundless works,
The power and passion leaping from its calm,
The rapture of its movements and its rest,
And its fire-sweet miracle of transcendent life,
The million-pointed undivided grasp
Of its vision of one same stupendous All,
Its inexhaustible acts in a timeless Time,
A space that is its own infinity.