Hi preethaa, I don't think there is any rule regarding the the built-ins. I've seen some spaces where they've done some really amazing things with built ins, like photograph murals placed on simple flat front cabinet doors. I think it depends a lot on the space, the style etc. Probably the safest bet is to paint the built ins the same colour as your trim. It is a classic look and you will not tire of it.

With white fixtures, keep your floors and all tile white or a stone that is mostly white. You can paint the walls above the wainscot (which might be glossy painted wood or beadboard, or you might employ a cabinet for the sink that was painted a very soft sky blue. One narrow trim piece of tile running through the white tile might be the same tone of sky blue. Then, add blue linens / towels / etc. [houzz=] Now, consider what other colors are in your home and select one that is clear and soft and lovely with white. You might use that color instead of sky blue. I used sky blue because it is the color of water and therefore always appropriate in the bath, but you can make the bath flow with the colors you have or plan to have in your home. If this was a master bathroom instead of a common or guest bath, I would shift the choices of stone and tile from white plus white to a lovely off-white, cream, or almond tone - like travertine. Use a neutral like chocolate on the cabinet and add color only with linens and perhaps some art on the wall. [houzz=]

Your drapes look like they're fine. It's hard to see if they're long enough--do they just touch the floor? That would be the right length. Make sure the paint you pick blends with the color of the drapes and the two chairs. The Edgecomb Gray looks like it would work or you could go with an entirely different color and add pictures and rug to pull it all together. Love the color Sea Salt by SW.

What a beautiful house, Shahbaaz! I live in a similar house - a 150-year-old colonial bungalow in Kumaon. You have already received lots of excellent advice from better-qualified people, so all I would say is, keep its age and heritage character the central theme. The white tiles do clash, I am afraid ... flooring with terracotta tiles would echo the roof and look lovely. The columns and the arches over the doors and windows are amazing. But I'd say, leave it all chuna-painted - there's a beauty and softness to it. Don't let the painters add too much neel (indigo) in the limewash -- in the hills where I live, they put far too much if I don't watch out and the result is a harsh white. Natural lime has a softer, creamy look.