Annotation by P-num or ss-count values.
Annotation by probabilities of of base pairing is not (yet) available on the mfold web server.

Hex	% P-num % ss-count	Probability
ff0000	0.0-2.5	0.999
ff1f00	2.5-5.0	0.998
ff3f00	5.0-7.5	0.997
ff5f00	7.5-10.0	0.997
ff7f00	10.0-12.5	0.995
ff9f00	12.5-15.0	0.994
ffbf00	15.0-17.5	0.991
ffdf00	17.5-20.0	0.988
ffff00	20.0-22.5	0.984
dfff00	22.5-25.0	0.978
bfff00	25.0-27.5	0.969
9fff00	27.5-30.0	0.958
7fff00	30.0-32.5	0.943
5fff00	32.5-35.0	0.923
3fff00	35.0-37.5	0.894
1fff00	37.5-40.0	0.856
00ff00	40.0-42.5	0.803
00ff3f	42.5-45.0	0.731
00ff7f	45.0-47.5	0.634
00ffbf	47.5-50.0	0.500

Hex	% P-num % ss-count	Probability
00ffff	50.0-52.5	0.500
00bfff	52.5-55.0	0.366
007fff	55.0-57.5	0.269
003fff	57.5-60.0	0.197
0000ff	60.0-62.5	0.144
1f00ff	62.5-65.0	0.106
3f00ff	65.0-67.5	0.077
5f00ff	67.5-70.0	0.057
7f00ff	70.0-72.5	0.042
9f00ff	72.5-75.0	0.031
bf00ff	75.0-77.5	0.022
df00ff	77.5-80.0	0.016
af00cf	80.0-82.5	0.012
7f009f	82.5-85.0	0.009
5f007f	85.0-87.5	0.006
3f005f	87.5-90.0	0.005
1f003f	90.0-92.5	0.003
09001f	92.5-95.0	0.003
040009	95.0-97.5	0.002
000000	97.5-100.0	0.001