An old elevator would excite me more!!

If there is a storage cupboard underneath the stairs, then I think its best to let go of the open risers. At the end of the day when it comes to stairs, I think you need to make simple decisions, don't complicate it. Sometimes spaces fuss over stairs and they can look great, but they are very impractical, expensive and dangerous. I think if you live in a house with no kids and no elderly, then you can lash out and go for something with more design risk. I think the timber stair profile shown in your picture looks great, and would work well with your vertical timber beam balustrade. However timber stairs can be noisy and quite slippery. If you are using carpet upstairs then you could consider running carpet all the way down the stairs. Don't do the half half thing. In order to finish the edge of the stairs neatly, I would edge the stairs with the plaster finish continuing from the cupboard wall, all the way up to the edge of the stairs and making an edge profile for the carpet to be neatly tucked into. By doing this you could still get the stepping silhouette which would look very cool. Then the beams could run off the plaster surface and not the edge of the carpet. Ultimately carpet may be annoying to have to vacuum, but it is a lot quieter, considerably cheaper and safer than timber stairs. Hope that helps. Good luck with it.

We have timber stairs though downstairs is retail. Being clumsy I've had to put in anti slip aluminium strips on mine . Hubby reckons they look ugly but I do not want to slip all the way down the stairs. have done it on our steps before and stuffed up my ankle. I would carpet it unless you've got lots of room for a big staircase . A narrow one in timber is very dangerous.

HU - I really think you should start a new thread on this issue as, many people may not see this when it is an old thread. I've had different colours of the exact same carpet in a house, but there were rooms in between so it was never obvious, but two different carpets together is another thing again. How did you feel the green looked with the off white?? If you were happy with the two colours together, then you could put any colour you liked with it, otherwise maybe remove the carpet from the stairs, although that can then make the stairs very noisy. What is the condition of the off white carpet - do you feel it may need replacing soon so you could match whatever you do now, if it is a carpet that does not look like being discontinued in the near future. You may even be able to match the off white that is there. Another hassle with using two different carpets is the weave and texture can make them look more odd together than different colours. It is really hard to advise you on this, you really need to see the two carpets together, at least it is easy to bring home carpet samples to see just what you can live with. Good luck.