The Brave browser is another one that does very well: it supports the ICC4 color standard and its other scores (528, 3187) are the highest so far.
I repeated all of the tests with the 32-bit edition of Win7 Home Premium on a different machine. The Peacekeeper scores are
Avant Ultimate (Chrome)...62.0.3202.94.....2798
Brave.............................. 63.0.3239.132...2843
Google Chrome.................63.0.3239.13 2...2757
SRWare Iron....................63.0.3300.0 .......2890
Vivaldi............................ .62.0.3202.97.....2779
Most of the version numbers don't match, so we can't really say which browser is "best", only that they are all very good.
Because Edge and Safari perform poorly on the HTML5 test
https://html5test.com/results/desktop.html
there's probably no reason to investigate those browsers further.
- sutekh