I tried as above, it doesn't make any difference.
I also tried using Template Option > Typography, whilst it does fix the hover color problem, it creates other problems by overriding my other CSS for the main menu. I have 26 lines of code in my custom CSS file for the main menu. Everything is working, except active and hover. Active and hover is working correctly in dropdown menus and in the offcanvas menu, and is using my custom css file.
By the way, I noticed a 2.0.4 upgrade was available, so I've installed it and it didn't fix the problem.
The below code is from by custom.css file, it worked perfectly up until the 2.0.3 release.
#sp-header .sp-megamenu-parent > li > a {font-weight: 400; font-family: 'open sans', sans-serif; font-size: 16px; color: #424242; }
.sp-megamenu-parent > li.active > a, .sp-megamenu-parent > li.active:hover > a { color: #00713d; }
.sp-megamenu-parent > li > a:hover, .sp-megamenu-parent > li:hover > a { color: #00713d; }