Hello, I recently made a SimpleSlides presentation with MKIV (2011.08.27 13:24). It looks ok on numerous PDF readers including Okular, Google Docs, Sumatra PDF. Whenever I open it on Adobe Reader, the results are rather puzzling: 1) The fifth page background is not black but grey, also some later pages have grey background 2) The RGB and CMYK swatch colours are all messed up The picture on page four has been intentionally corrupted with a hex editor and then opened and saved again in Gimp to remove the errors in the file. You can view the source here: https://pi-xi.net/share/colorlecture.tex and the finished PDF here: https://pi-xi.net/share/colorlecture.pdf The only modifications I've made to the simpleslides-s-BottomSquares.tex is replacing the background color, contrast color and variant color with different values ([s=.0], [r=.8,g=.2,b=.2], [s=.15]). I would appreciate if someone could explain if there are bugs in my tex sources, in MKIV or in the Adobe Reader – and in any case how can I fix the erroneous output on Adobe Reader to match it on Sumatra, Google Docs, etc. Best regards, Otso Helenius