Save For Web is not designed for big files. This is for screen-sized images for web or mobile devices, 800 - 1500 pixels or so.
For larger files, use a regular "Save As" to jpeg.
That said, the new Export module should handle large files better - but this is still not intended for anything other than screen-sized images.
That makes alot of sense, didn't think about it that way. However I remember a few years ago on my old pc resorting to doing just that and for some reason whenever I uploaded my files to dropbox and viewed/download them on my phone the color was way off. I suppose I could try it again and see but that was the reason why I never did the save as method.
The purpose of Save For Web is to optimize fast loading on the internet - you can try different file compression methods and directly check visual impact and upload times.
As for color - convert to sRGB and embed the profile. There are checkboxes for that.
I had those options checked off, which is what had me confused, I did a bunch of things to try to figure out why the color shifted, and nothing seemed to be the answer. It may have been my old phone causing issues too maybe. I'll give it a try again and see. Thanks.