deep bright blue

[Mher]

Hi, people. What does the author intend to say by using this expression?

"Around in every direction it was still as black as pitch, but nearly overhead there burst out, all at once, a circular rift of clear sky — as clear as I ever saw — and of a deep bright blue — and through it there blazed forth the full moon with a lustre that I never before knew her to wear."
So, is it deep blue or bright blue?

 

[Tdol]

Hard to say- possibly at the darker end of what could be called bright blue as it's a sky, a richer blue than normal.