Adobe won’t give you colors except as “fractions out of 256″.
Apple won’t accept colors as anything except “fractions out of 1.0″.
Who has the time for this? . Normally I do it in my head, but I’m fed up of doing “division by 256″ when talking back and forth with designers and coders. For $1 … to avoid the mess courtesy Apple/Adobe … it’s worth it.