Hex Opacity Values

#AARRGGBB
AA is the alpha channel
RR is the red channel
GG is the green channel
BB is the blue channel.

0 (fully transparent) to 255 (completely opaque - dark)
20% Opacity => 255 * 0.2 = 51 ==> in hex 33

100% — #FF (Dark)  - # -> 0x
95% — #F2
90% — #E6
85% — #D9
80% — #CC
75% — #BF
70% — #B3
65% — #A6
60% — #99
55% — #8C
50% — #80
45% — #73
40% — #66
35% — #59
30% — #4D
25% — #40
20% — #33 - 255 * 0.2 = 51 ==> in hex 33
15% — #26
10% — #1A
5% — #0D
0% — #00 (Transparent)