Qutebrowser supports custom CSS overrides. For example I have a CSS file for dark mode that replaces colors in certain html tags, but you could easily just change the color values for something lighter.

Of course it's also not perfect as it'll do that on all sites and qutebrowser isn't everyone's cup of tea.

I have a Bookmark with this as the "URL". I call it "Zap colors". I forget where I found it from. But I use it on the

javascript:(function(){var%20newSS,%20styles='%20{%20background:%20white%20!%20important;%20color:%20black%20!important%20}%20:link,%20:link%20%20{%20color:%20#0000EE%20!important%20}%20:visited,%20:visited%20*%20{%20color:%20#551A8B%20!important%20}';%20if(document.createStyleSheet)%20{%20document.createStyleSheet("javascript:'"+styles+"'");%20}%20else%20{%20newSS=document.createElement('link');%20newSS.rel='stylesheet';%20newSS.href='data:text/css,'+escape(styles);%20document.getElementsByTagName("head")[0].appendChild(newSS);%20}%20})();

Dark Reader actually had a light mode theme option — not sure how well it works on making dark pages light. But I’ve used the light mode with the contrast slider cranked up to make some pages easier to read! Probably worth a shot