I had an accident ten weeks ago. I had slight bleeding of the brain and had stitches, but these were taken out after a few days. The scabs came away a couple of months ago. The skin has healed up and I have no open wound, but there are still a couple of bumps, which feel a little tender to the touch. I was suffering from some dizziness with sudden movements to the head and sitting up in bed, but this has gone now. My grey roots, which I used to colour every month, are getting quite conspicuous now. Is it safe for me to start using hair colour again?