Looking for a wool hooded base layer.

This is why BPL came out with their hoodie, to fill a gap in the market. The Icebreaker Atlantis is the only other lightweight wool hoodie I know of, but it's got that full zip and, like you say, is only available in dark colors. The other option would be to look at custom sewing one. There's a member in the MYOG forum who did this using two Patagonia Wool2 base layers (he cannibalized the second one to make the hood). If your sewing skills aren't that great, you might still check the yellow pages for seamstresses and check with them about their rates. If you design the patterns and provide the materials, it might not be too expensive.