Please help me 
I need (ok want) to start colouring my hair to cover up a few gray hairs. I can't afford to have it done at a hairdressers so I'll have to resort to home dye
But there are so many to choose from! I don't know where to start, and I don't know what colour to get. Do you just pick the colour you like the best? Or does it have to match your own or your skin and eye colour
I am incredibly ignorant of anything like this so please take pity on me and talk slowly 