Instead of the solid grey, you can go for sketches in grey with flashes of mustard/ yellow. Or, look up these links for wallpaper ideas https://goo.gl/images/OrCtY1 https://goo.gl/images/0ZpAmU

I would suggest u to go with white sheer and light grey curtains only. If u want want to play with bright colours then it is safest if u add them in form of accessories or decors, reason one being the space is small n it’ll look more crowded then. It’s better if u avoid orange n yellow in this bedroom at least. If u can give a better picture of the accent wall colour here it would be better. Then u could go with a darker shade of it to form the colour scheme. White+Grey+Purplish brown. That’s it.

Hi not clear about furniture color combination...we have to think about over all color combination... if you like grey color go with lighter shade like Gentle grey...here attaching some reference images take one combination.

Hey Nidheev, There are multiple options you can use to achieve this look. POP Moulding Strips are the best option for you. they hold paint well and you can find them in different shapes if you want to add a little to the design. You can use wooden strips (As reinventing interiors mentioned, lipping patti, as it's called in the west). The problem with that is that wood won't hold the wall paint you apply on top. it cracks very soon after application. In addition, wood will expand and contract based on the season making the cracks wider. It is also worth mentioning that the wooden stips that you can apply directly without a carpenter will not be wide enough for the design. MDF is another option but it needs to be worked on by a carpenter. as you will not get the size and thickness you require. It is a better option compared to wood as it will hold paint for a little longer. Although you will get cracks eventually. Lastly, you can buy a large sheet of Gypsum board and get a false ceiling vendor to cut and put it up in your walls. A 6mm Thick sheet should be perfect for you. I hope this helps! Best Miloni