Here's a correct table of percentages to hex values. E.g. for 50% white you'd use #80FFFFFF
Using the below values one can achieve transparency in any color.
AARRGGBB where AA represents the alpha value and can be replaced with hex values from below table to achieve desired transparency.
- 100% — FF
- 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
- 15% — 26
- 10% — 1A
- 5% — 0D
- 0% — 00
Taken from SO for my future reference
