Question

what kind of nebula are typically blue in colour

Answer 1

The reflection nebulaes are typically blue in color.Reflection nebulae are clouds of dust which are simply reflecting the light of a nearby star or stars.They are usually blue because the scattering is more efficient for blue light. Reflection nebulae and emission nebulae (Red in color) are often seen together and are sometimes both referred to as diffuse nebulae. (NGC 7023 shown).