There is a simple way to work it out:
This is how the colour values are derived... the RGB palette has originally a range of 0-255 for each channel. However, in the code form, 0-1 is used instead.
Now let's read the line again,
colorText[]={0.23,0.3,0.08,0.75};
Knowing that, one can easily convert these values to and fro.
R channel : 0.23/1.00 * 255 = 58.65
G channel : 0.3/1.00 * 255 = 76.5
B channel : 0.08/1.00 * 255 = 20.4
I usually round up the numbers.
- Raymond Koh
So, in your picture editing program, if you open up the colour palate, you'll see the boxes for the RGB values and can work them as following:
eg. R = 59 59/255 = 0.23
G = 80 then 80/255 = 0.31
B = 2 2/255 = 0 (or 0.007)
And that's how you get your colours.