Problems with the (old) standard colormap in Matlab are widely known. Even MathWorks addressed this issue after changing the default colormap in this blog post. But there are several other sources that discuss this issue or provide better colormaps. Most of them just a short Google search away (e.g. here, here or here).
The de facto standard source for good colormaps is ColorBrewer developed by Cynthia Brewerbased on the research of Dr. Cynthia Brewer. To use these maps in Matlab, you can use BrewerMap by DrosteEffect.
To summarize some of the different colormaps, I chose some typical numerical results that I often have to visualize. These are visualized with different ColorBrewer maps, as well as with jet for comparison.
The first example is the checkerboard test case. A source is placed in the middle of the domain and emits radiation in a heterogeneous environment. As for all further pictures: everything is the same but the colormap. The checkerboard results are shown below.