finding out brightness of color
Is it possible to find out how bright is an color? I need to find the darkest color in document's swatches. My solution would be to convert (script internally, without actually making any changes in document) swatches to grayscale, compare them and pick the darkest. But how to convert swatch defined in undefined mode (they might be in lab or cmyk) to grayscale?
I found in 'js scriping reference' a method "convertSampleColor", but I have no idea how to use it. Any examples?
