Is the sky blue?

It is Cian during the day and black during the night.
Daylight is coloured by Rayleigh scattering of light and so are the other effects like red in the morning and night and local effects like rainbows.
Lord Rayleigh is a nobel Laureate

The sky appears blue because sunlight shining on the earth encounters earth’s atmosphere in which is suspended tiny particles of water, water vapor, and dust. As light rays transverse our atmosphere some of the rays strike some of the particles and some don’t. It’s the size of the particle and the wavelength of the light ray (color) that determines a hit or a miss. Now blue and violet light rays have the shortest wavelength. Thus blue and violet have a higher probability of hitting something. The other colors with their longer wavelength are less likely to collide. It is particle impacts that scatter the blue and violet light and this scattering is what you see i.e. a blue sky.

You can look this up. This light scatter is called Rayleigh scattering after a famous British scientist that studied and publish his findings. Lord Rayleigh is a Nobel Prize Laureate.

The sky is gray, it just looks blue.

No it is not! You are seeing it as blue color because of the chemical reactions and other gases.

yes

No, the sky is colorless other than the dirt and dust. The Nitrogen in the atmosphere is what gives our sky its blue color in daylight. Light waves and absorption.

The Sky is Transparent(clear) . The Sky is blue during the day(Rayleigh scattering) and black at night(due to no sunlight).

The sky has no color. There is no physical object or surface that is the sky. "Sky" is merely the term we give to the empty space above our heads that continues out to the edge of the universe.
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Depends on the time of day. And, never for dogs.

no. the sky is just a near version of space.It looks blue in the day because the atmosphere of earth dissipates all the wavelengths other than blue which reaches our eyes and makes atmosphere look blue to us

It is Black.
But from the surface of the Earth it looks "blue" because of the atmosphere scattering the Light to Blue.

Here in the UK it's dark so the answer is no.