Apologies for the lack of updates in recent months. With my new job and new hair the HT forums have taken a bit of a back seat in my life.
Martinvain - Didn't see your question until now. I used concealer probably about a month or so after my HTs. Basically, I used it when I felt there was no danger of it irritating the skin (ie when it was 100% healed). I used a variety of different concealers. Not sure if this is recommended by the docs or not.
I am coming up to a year after my 2nd op so I thought I would put in an update. The below pics are taken with no product in my hair.
I have found in the last few months that the quality of the hair is improving and it is taking on the characteristics of the surrounding hair even more. I have a new girlfriend who plays with my hair and has absolutely no idea that I have had anything done. In fact, she asked me the other day if I thought I would ever go bald... heh.
In short, I am absolutely delighted. I know that as my hair loss progresses I will have to get another HT at some point and BHR will be my first port of call.