Show monochrome image popups in monochrome threads

boards/static/css/base.css

@@ -144,7 +144,7 b' textarea, input {'
     opacity: 1;
 }
 
-.monochrome > .image > .thumb > img {
+.monochrome > .image > .thumb > img, .monochrome.img-full {
     filter: grayscale(100%);
     -webkit-filter: grayscale(100%);
 }

boards/static/js/image.js

@@ -184,6 +184,9 b' PopupImageViewer.prototype.view = functi'
             newImage.click(function() {
                 $(this).remove();
             });
+        if (post.parent().parent().hasClass('monochrome')) {
+            newImage.addClass('monochrome');
+        }
     } else {
         existingPopups.remove();
     }