How do you dye or colour your hair naturally eg: lemon juice?

Lemon juice will not dye your hair. Years ago it was used as a brightener for skin and hair but will not make any significant changes.

Tick

Okay
Well lightening the hair will be good as well
Is that all??

What do you mean is that all ? If you are expecting 'signifcant' you are not going to get it. If your hair is say, naturally light blond, brown, whatever, then it will look brighter.