You could head to Ikea if you're lucky enough to have one near you. Their Billy bookcases with the added height pieces are wonderful and are available in a black/brown color.

I think all white will be a very nice scheme and the differences in the white will just add subtle difference. In the above pic the walls are more white than the table, but mixing with the light tan colours and greyish tones makes this gradient of whitish tones work well.This room is all white as well with the furniture and walls, but adding the punch of the other colours masks if the whites are slightly different as the bright colours become the focus. The walls in the pic below 'read' a very pale grey so that would be an option, just ensure that it is a whitish-grey and not muddy or warm. I would choose the sofa colour as your main colour and accents to match from there.

Hi, I am from Assam, Guwahati. Yes it is warm humid place with lot of rains (like kerala). The bookcase is gradually drying. Fortunately last few days were very sunny and airy and my room has two big windows. Few mor details of my bookcase. It is 8 feet wide, 6 feet tall and 11 inch deep. It was attached with wall with 6 wall screw and has four pair of legs.I ask the carpenter to divide the bookcase into 3 part (32 inch each) and two door system for each part. Every part has 6 shelve from top to botom. There is no plywood or wood in back. I made it that way because the bookcase is attached in my room's inner wall I understand that the bookcase may have very little gap in between wall and wooden planks and i am ready for it. But I have no idea that beacuse of faulty mesurement, it became 1 inch gap between wall and sheve in the upper side. In lower side it is very minimum gap. I stop the carpenters to put the glass door. But now I see that they also make fault in making the doors. The doors are heavier that the shelf. The wooden planks are 1 inch thick while the door are 1.1/2 inch thick. I actually visit few hardwere shops here, but most have no ideas what to do and few says to apply wall putty to fill the gap. But my back wall is coloured (old wall, that why) and wall putty will not set on old wall and timber. I cannot remove it now from the wall otherwise the wall may destroyed. I really need a step by step guide now that what to do after the heves are dry, how to fil the gap and how to put the door without further damaging the shelf.

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...