Android uses Hex ARGB values, which are formatted as #AARRGGBB. That first pair of letters, the AA, represent the Alpha Channel. You must convert your decimal opacity values to a Hexdecimal value. Here are the steps:
Alpha Hex Value Process
- Take your opacity as a decimal value and multiply it by 255. So, if you have a block that is 50% opaque the decimal value would be .5. For example: .5 x 255 = 127.5
- The fraction won't convert to hex, so you must round your number up or down to the nearest whole number. For example: 127.5 rounds up to 128; 55.25 rounds down to 55.
- Enter your decimal value in a decimal to hexadecimal converter, like thishttp://www.binaryhexconverter.com/decimal-to-hex-converter, and convert your values
- If you only get back a single value, prefix it with a zero. For example, if you're trying to get 5% opacity and your going through this process you'll end up with the hex value of D. Add a zero in front of it so it appears as 0D.
That's how you find the alpha channel value. I've taken the liberty to put together a list of values for you. Enjoy!
Hex Opacity Values
- 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
refer Understanding colors in Android