K.T.
I am 40 also and just started to get a few white hairs ( I am a redhead). Luckily I do get blonde highlights at the hairdresser. However, I do color my teen daughters hair and a few friends with the demi permanent color at home. It is super easy and washes out gradually. I suggest Loreal. If you have a Sally's beauty supply that is the best place to go and they can help you pick everything you need and answer any questions you may have. Very inexpensive and you can do it alone of have a friend of family member help. Good Luck!