Looks like you may already have a little bit of color blocking going on, but I'd increase the contrast between the shades of paint. Do you have access to the original paint chip card? Paint two of the walls in question in two different shades from that same card. Consult with the paint source for the complimentary color to accent the third wall. I think the middle wall to the right of the stairs would be the one I'd accent. Then add a large piece of colorful abstract art to that wall. Here's a quick tutorial on color blocking. https://www.houzz.com/magazine/building-with-blocks-of-color-stsetivw-vs~639

Hello Yuvraj, We would recommend a different color mostly charcoal black or dark brown for your stair railings. Nitin Cornerstone Designs, Bangalore.

We are an online homes styling and staging company. We do space planning, furniture layouts, reuse/ repurpose old furniture with the new ones, make design boards and suggest easy solutions with great makeovers. You can check some of our work on our profile on Houzz. You could also get in touch with us on 9923893771 or email us at reema@cubspaces.com Happy Colouring! regards, Team Cubspaces

Just because you want to use the space below the stairs, do not just add drawers or shelfs unless you reaalllyyy need it. I would suggest go for adding something green to your house. Its healthy by adding air purifying plants. These plants are nowadays available in most of the nurseries and moreover Green patch in the house gives a beautiful look to the house and is also good for eyes ( the green color). Below are few picture to motivate you for Green patch or Indoor garden.