You've got your hands full on this one!! The green is a good color, but I question the advisability of the harshly contrasting black furniture you plan. As far as painting and keeping ceilings looking high, bite the bullet. You have to paint all the walls floor to ceiling.

To go with green, choose a color that's not so bright and more moss color. Bright colors will overwhelm the room. With the high ceilings, walk around each wall to see where color can change - cut off to another color. Make your ceiling 30% lighter than the walls using the same base color. Do your main walls in a stronger color and lighten by 20% for areas that don't get a lot of natural light.

If you like the green, pick the green. I have a lovely green olive shade in my bedroom that was chosen by my niece and I love it. It goes wonderfully well with bright white trim, white draperies, dark wood furniture and marimekko prints on the duvet. Search houzz and find as many rooms in a green that inspire you & make you want to live there & build your room in a similar fashion. You want to make sure that your furniture is not too large nor too small for the room -- if you haven't many square meters, then shop in places that specialize in furniture that is scaled for flats rather than mansions.

Drama!

traditional

Thanks for ur advice guys ! Is there any other color advice ? Like brown n beige mix . Will it suit the high walls . I seriously don't have any idea as how to use the color . I tried a green on the walls in Photoshop . It looks totally lame but just want to know how to mix the colors . Any suggestion on how and where to use the color will be appreciated . Like dark color on the wall which has the TV and light color on all the other walls or opposite walls with the same color .. Pulling my hair out !!!

I wanted to go for the black sofas only cos of low maintainence . It wil not get dirty soon .

The one big thing under the staircase is my fish tank . The one near the wall is the TV . Yes we have fans attached on the walls . Since we have a high roof , we cant use ceiling fans . And the house is not equipped with a centralized AC .

I just want a color which will helps me relax and will also look modern .

That vibrant green will not help you relax, but you figured that out already I guess. Softer colours are more soothing. Black will get dirty just as fast as other colours, only it doesn't show as much.
What colour is your floor?

Browse through Houzz photos and save the ones you like to your ideabook. It will help you get a better idea of what will work for your room. You may want to think about your lighting too. The TL light tubes on your walls will not provide a nice, relaxing light.

Here are lots of rooms that you can browse through:
http://www.houzz.com/photos/living-room/two-story-stories-high-