# Bug with exporting Image/Graphics into CMYK JPEG?

While answering the question (123118), @RussLyons pointed out that exporting graphics and images in CMYK JPEG does not function correctly.

For instance:

p = Graphics[{CMYKColor[1, 0, 1, 0], Rectangle[]}];


Exporting the graphics in CMYK results in a black rectangle.

Export["test.jpg", p, "JPEG", "ColorSpace" -> "CMYK"];


Importing the JPEG back in Mathematica works.

Import["test.jpg"]


I know that JPEG files support CMYK color space but Mathematica seems not to be doing this correctly. Is this a bug with Mathematica 's Export function?