L'Oréal wild ombré intense. This is what I use to colour my hair. I find this product very easy to use and it only takes one hour for application and development. It is a very reasonably priced kit (around £7) and it is so easy to use with clear instructions. The kit contains everything you need to achieve vibrant ombré hair at home, including the brush for application and the conditioning shampoo for use when you have rinsed the dye out. This kit is designed for a more intense result, I have tried the normal ombré kit and I would say that this one achieves a much more intense effect and lasts for much longer without fading.
The one downside to this product is that it can leave your hair feeling very dry, which is understandable since you are effectively bleaching you hair. When you have rinsed the dye off thoroughly with warm water, use the conditioning shampoo provided in the kit. Lather it through all of your hair, then when you have rinsed it out, apply a deep conditioning treatment to your hair such as Tresemmé Restructuring Deep Conditioning Treatment Masque. Leave on for a good 5-10 minutes so that the conditioner really gets to work it's way into your hair, then rinse out. I always give my hair a final rinse in cold water too, as it prevents frizz and really seals the conditioner into the hair. Towel dry and then apply a small amount of serum whilst your hair is still damp (such as John Frieda Frizz Ease) then blow dry as normal for lovely sleek, ombré hair!
Ombré hair kits are available at most Superdrug and Boots stores as well as at supermarkets.