The North-West was given green as its colour, but the shakti chakra shows it in blue. Why?
The colour on the chakra is the colour of the devta of that zone, not of the element; the North devtas are shown in red, for example, which is not a colour to paint there. The air element has both green and blue as its colours.
Related questions
Can a bedroom be made at Shikhi (E1), and why should it be white rather than red?
Yes, a bedroom at Shikhi can suit elderly people, and it should be painted white rather than the zone's red colour, as advised for people of kapha nature and for those of pitta nature whose heat rises quickly. Shikhi is highly sensitive and already hot, so red would add heat and open the third eye.
Can blue be used in the North-West?
Light green or a shining lustre white is better than blue in the North-West.
Should each zone of the house be painted in the colour of its devta?
Colours are taught in interior vastu; do not get confused now and focus on what is being taught.
Why is the colour of Bhrisha (E7) dark blue when blue is usually avoided in the East?
Where there is heat, coolness is given, and where there is cold, heat is given; heat added to heat burns things out and cold added to cold also ends them. It is like swar, where the cooling chandra swar should flow in the body while the Sun is up. E7 lies next to the fire (Agni) corner, so it was given blue.
Can a false ceiling be painted blue, and will it cause problems?
Light sky blue that matches the colour of the sky can be used and causes no problem. If the blue is dark, paint small twinkling stars on it to nullify its effect.
Can the kitchen platform be painted?
Yes, the platform can be painted, but the type of paint matters, which is explained in the topic of paints, pigments and colours. Never use oil-based paint.