Question

How can I convert colors from (N, N, N) format to #AABBCC (and #AAABBBCCC) ?

thanks

Answer 1

#FFFFFF, so simple

every single char has 0..F range. That is 0..15. So two chars is 0..(16*16-1) -> 0-255

To convert between formats just think about:

#AABBCC are three values AA BB CC. Every single value represents a channel (red, green, blue) that can span from 0 to 255 or from 0 to FF or from 0.0 to 1.0

if you have for example #123456 you can do

12 -> 1*16 + 2 = .. (result in range 0-255)
34 -> 3*16 + 4 = ..
56 -> 5*16 + 6 = ..

in general a two digits hex number composed by XY can be converted to an decimal value by multiplying X by 16 and adding Y, taking care of converting digits that are over 9 (A, B, C, D, E, F) to their counterparts (10, 11, 12, 13, 14, 15). So for example AC would be A*16 + C = 10*16 + 12.

(To be really precise a n digit hex number is converted by multiplying the i-th digit from right by 16^i and adding all of them together)