gistfile1.js

// requires axs_testing.js from https://github.com/GoogleChrome/accessibility-developer-tools

accessible = {};

accessible.highContrastMode = function() {
 var elementsWithText = $('body *:not(:has(*))').filter(function() {
    var $this = $(this);
    return $.trim($this.text()).length > 0 && $this.prop('tagName') !== 'IFRAME';
  });

  $(elementsWithText).each(function(i, el) {
    var properties = axs.properties.getColorProperties(el);
    if(properties.contrastRatio.suggestedColors && properties.contrastRatio.value < 4.5){
      el.style.color = properties.contrastRatio.suggestedColors.AA.fg;
      el.style.backgroundColor = properties.contrastRatio.suggestedColors.AA.bg;
    };
  });
};

accessible.highContrastMode();