Hex Colors in Android are some times 8 digits. How? What is the difference between #FFFFFF and #FFFFFF00

Question

I sometimes have seen in examples where the coloring in Android is done as #FF191919. I mean a 8 digit hex number . But it should be only a 6 digit number. How are they rela

Answer 1

AN 8 digit Android HEx is called an aRGB. aRGB values are typically expressed using 8 hexadecimal digits, with each pair of the hexadecimal digits representing the values of the Alpha, Red, Green and Blue channel, respectively. For example 80FFFF00 represents 50.2% opaque (non-premultiplied) yellow. The 80 hex value, which is 128 in decimal, represents a 50.2% alpha value because 128 is approximately 50.2% of the maximum value of 255 (FF hex); to continue to decipher the 80FFFF00 value, the first FF represents the maximum value red can have; the second FF is like the previous but for green; the final 00 represents the minimum value blue can have (effectively – no blue). Consequently red + green yields yellow. In cases where the alpha is not used this can be shortened to 6 digits RRGGBB, this is why it was chosen to put the alpha in the top bits. Depending on the context a 0x or a number sign (#)[1] is put before the hex digits.