# Jumping colors in beamer presentation

I have a very strange problem in my beamer presentation:

I create a lot of tikz pictures externally and then include them as pdf pictures in the presentation. If you look at these pdf documents individually they all have consistent colors. However when you looking at the presentation, the colors "jump" from slide to slide. So what was blue in one slide will be a slightly different shade of blue on the next one.

The problem appears in Adobe Reader, in Okular everything seems to be ok. Unfortunately I cannot provide any simple example to reproduce the error, since it only happens sometimes and I don't really know what causes this. There also seem to be differences between Adobe Reader versions, but I have not systematically investigated which versions work/do not work, since the effect is pretty rare.

One suspicion: It seems to only happen for standard colors, which I call via "blue" in TikZ. Could it be that the saved pdf has saved that the color is "blue" and that color name gets interpreted differently on each slide?

I know this is a rather vague question, for the simple reason that I have no idea what causes this. Has anyone experienced a similar problem before and knows the solution?

• Probably a problem of colour spaces. Can you make a minimal working example (MWE) that reproduces the problem? Explicitly passing a colour mode to the xcolor package could help or to use \selectcolormodel{...} – user36296 Nov 2 '18 at 11:21

You don't show us any code to test, so this is just a guess (Just to be clear: I did not steal @marmot's crystal ball)

I think the problem is caused by different colour models used in your images and your presentation. To unify the colour models, you could explicitly set it to something with matches your images. I.e. if the colour model should be RGB you could do

\documentclass{beamer}
\selectcolormodel{RGB}

\begin{document}

\begin{frame}
...
\end{frame}

\end{document}


or

\documentclass[xcolor={RGB}]{beamer}

\begin{document}

\begin{frame}
...
\end{frame}

\end{document}

• Certainly a good guess, because it solves the problem with the included figures. Interestingly it made me realize that my description wasn‘t quite right, there are also jumping colors that are not in included figures. And those ones are not fixed yet. I‘ll try to make a minimum working example as you suggested and come back with that. May take a while though ;) – Wolpertinger Nov 2 '18 at 13:28
• Your solution together with tex.stackexchange.com/questions/16061/… solved my problem. Thank you very much! – Wolpertinger Nov 5 '18 at 17:12