
Why you would want to create your head textures in CMYK is beyond me. CMYK is a printing color mode, and it will even limit the number of filters available to you... RGB is your best bet for screen/display work.
However, I just tested CMYK color mode for .jpg... and it uploaded fine.
However, I tried to upload a LAB color mode TIF (no compression) and it will not upload.
File:
http://www.mediafire.com/file/iwo2yomqvgl/head.tif
*Edit*
TIF in RGB does not work either... which is TIF's default (well, most people work in RBG whether they know it or not) and more functional color format for this application...
TIF in RGB:
http://www.mediafire.com/file/yjmttmyc4zf/head.tif
*Edit Edit*
It tells "Make sure the file format is in the allowed extensions list", which TIF is...
" Accepted image formats: .BMP .GIF .JPG .PNG .TGA .TIF"
So after testing in RGB, LAB, CMYK, Grayscale, Multichannel, Indexed, Duotone, and Bitmap, it would seem that .TIF, in general, is not being currently supported.
i have never seen u on.......