Rectangles in pure RGB Red, Green, Blue, Cyan, Magenta, Yellow. Exported to PDF, let it open in Preview and it looks like the original. Now MacOS has some odd notions of how colors should be displayed, so RGB 255, 0, 0 in PPT shows on screen (in PPT and in the resulting PDF) as 251, 0, 7. But at least they're the same. .

convert rgb to cmyk without losing color