colors code in android are different

Question

The color white, as far as I know is defined as

#ffffff

but android defines it this way

#ffffffff

why the 2 extra f?

Thanks

Answer 1

Colour codes are usually defined in either 3, 6, or 8 characters.

#FFFFFF

means that it is in RGB format. However, you can also have

#FFFFFFFF

is in ARGB format, which means that the first two characters represent the alpha value. In other words, the first two characters represent the opacity.

Have a look at this answer for a Java method to calculate the alpha values.

Answer 2

The first two places define the transparency/opacity of the color.

Here's a correct table of percentages to hex values. Eg for 50% white you'd use #80FFFFFF.

• 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

Source