This a very old question, but a very interesting one. So here is the answer.
The theory says that there as many longer streak from steak X as there are X streaks.
For example theoretically we expect this kind of results:
100 single streaks B or R
50 double streaks BB or RR
25 3-streaks BBB or RRR
12 4-streaks BBBB or RRRR
6 5-streaks BBBBB or RRRRR
3 6-streaks BBBBBB or RRRRRR
plus 3 more streaks longer than 6 in a row.
You get the idea.