There are two different things getting confused here.
There's the Colormap. The default for that changed from jet to parula. As Steven said, you can easily change the default for that using the instructions he pointed to. The Colormap is used by objects which are converting numeric data into colors. Examples include scatter, surface, and indexed images.
Then there's the ColorOrder. The ColorOrder is used by commands which just want to create a bunch of different colored objects. Examples include plot and errorbar. The default ColorOrder also changed in R2014b, but neither the old nor the new ones have names. The old one looked a bit like jet, but it actually wasn't quite. To get the old ColorOrder back, you would need to do this:
set(groot,'DefaultAxesColorOrder',[0 0 1; 0 .5 0; 1 0 0; 0 .75 .75; ...
.75 0 .75; .75 .75 0; .25 .25 .25])
It will probably still look a little different because of the antialiasing. That softens the colors a bit so they don't pop quite as much as they did in old versions. You could turn off GraphicsSmoothing if you really wanted them to look just like the old days.
