The thing is no one ever uses one of these pallets. You start off with one maybe as a base and then adjust everything to get stuff just right. The Coolors UI seems to be good at that.
I love coolors. Just hit space bar to cycle. Once I see a color I like, I just lock that color and continue hitting space bar and locking colors till I have a full pallet :-)
This was very neat. What I'm about to say should not detract from that – this is probably one of the better palette tools I have used, if not the best.
But why on Earth would you want a user account and cloud storage for 15 bytes of colour values?
Presumably the colors have been purposely picked to have really bad contrast, look identical to colorblind users, or create some other sort of usability difficulty.
I like colourlovers.com as well. Feels more organic, less engineered. And those palettes are easier to use, since they are reduced down to a theme, rather than having a 20 color palette with no overarching theme.
That is just me speaking as a non-designer. It's much easier for me to say... go in and find a theme for Cinquo de Mayo in Color Lovers, then try to infer it from these flat palettes.
I think it's obvious that it doesn't offer anything different besides that it's another option than those sites. CL for example has palletes that aren't as easily copied and for the most part are used a lot inside their own system.
[1] e.g. http://www.colourlovers.com/, http://www.color-hex.com/color-palettes/