My first question will be: what is the utilities of this room? Who live in it? Age, gender? Is this room oriented by the North or South? East or West? What do you want to feel in this room? Serenety? Concentration? Spirituality? Energy? After all this answer it will be easier to help you. :)

mostly Indians uses brown varnish paints for their main wooden doors....I even don't know why they didn't use other colors...even in my house doors are given brown color wooden texture...

When dimensioning a classroom or teaching space, the best rule of thumb to produce both good sightlines and efficient layout is as follows: the space needs to be slightly rectangular, but NOT long and narrow. If X = 1, then Y should = 1.2 ideally, and no more than 1.5. Consider a comfortable space of 12 sqft. per student so if you have 6 students in a classroom then 72 sqft. + teaching space and walking space (60 sqft. or more) so say roughly you need 130 - 140 sqft. of space per class.

Keep things cool Cooler shades such as grey and blue help walls recede, making the room feel more spacious and light. Bring home the sunshine Light but warm colours such as terracotta or yellow can mimic sunshine and make a space feel bright and airy. Pale ceilings Keep the ceilings in a light colour to make the room appear larger and lighter. While white is your safest bet, you can opt for mint or sage green for a pop of colour.