I am not exactly sure what kind of shade your carpet is exactly, but these are all great colours to consider. Have a look at the image with the different colour pallets, go with opposites on that, if your carpet is more on the cooler side, choose a shade from the warmer shades and then vise versa. Then for your little boys room, a cooler blue is a nice touch. The picture with the half and half colours, blue and white is also a good touch and will go well with the carpet.

What colour are the walls? Stripey carpet isn’t for everyone, but you can look at carpets with a very subtle stripe in them, or if you are unsure then a plain carpet would perhaps be a better option for you. I love carpet runners with black edging but they tend to suit period properties rather than modern.

Agree about a wooden floor instead of carpet. Another good point is an independent supplier. You will have to visit a showroom, take some time to look through what is available and some of them will let you bring the sample packs home to try it against your furniture, etc. I have cream pure wool loop pile carpets (they came with the house) and they are a nightmare. Cat claws and impossible to get stains out properly. I have had seagrass, jute and sisal before. They were all impossible to clean. A hard floor with rugs is a much easier (if less cosy) option. Rugs can also be layered which adds warmth in winter. I think you are looking for a sand colour. Cream or beige is too light and impractical.

Without a picture it’s hard to say. As Isla says light is everything and it can really change the colour of a carpet. If the children are very young how about an engineered wood or LVT floor with a washable rug? For the stairs I love the herringbone designs which have a subtle pattern which helps with disguising any dirt.