I've never used the stuff personally but i believe you would encounter the same problem. With a shaved hair i fear the product would stand out more than your hair. Just my opinion.
Save yourself some money, go to Home Depot and just buy some paint and paint your head. I used that dermmatch garbage and as far as I could tell, it is dried paint. I put it on my hair and made my hair a dry curly mess with paint on it.
^ Demmatch is an amazing product you can achive fantastic results with. I am using it since years. I am assuming that you don't apply it right. Read this illustrated thread http://www.hairestorationetwork.com/e ... -pics.html carefully and follow the instructions and you will also be amazed of how great it works.
It really just depends on how thick your hair is and also how closely the color match is. If you dont have at least a bit of coverage/thickness and your hair is not matched up pretty closely with the dermatch color it's just not going to look right.