F4A,
In rivers, I've found a small pink SJ worm to work extremely well.

As far as lakes go during springtime, I think the color red is more important then the pattern when fish are keying in on bloodworms. A red chrironomid pupa pattern is hard to beat at this time of the year.
I posted this picture in a previous thread. This might give you a few ideas for bloodworm patterns.
SF