Which sites load, and which do not

The builder behind a site matters less than what it sends: HTML and CSS. Every platform in the test produced pages Recolor could read and repaint. Webflow: finsweet.com (98%) and webflow.com (87%) of the elements changed color under the default palette. WordPress: wordpress.org/news (27%), a dark page with few colors. Shopify: www.allbirds.com (29%), a store whose look comes mostly from photos. Squarespace: www.squarespace.com (9%), a photo hero with black and white type. Framer: www.framer.com (31%). Wix: www.wix.com (7%), a white page whose soft gradient is an image.

A low share is not a failure: it means the page has little color in CSS. Images, video, canvas and WebGL keep their colors, as How Recolor repaints a page explains. The Grey images switch shows them in grey so the palette reads on its own. To try a page that is not public yet, upload its HTML, as Loading a page describes.

Every site was loaded twice, with the page's scripts on and off. With scripts off, no computed color on any site moved by more than 0.02 in OKLab when the engine rewrote the page, which is too little to see. With scripts on, four sites restyle themselves while they load (github.com, webflow.com, www.allbirds.com and www.squarespace.com), so the same check could not come out exact for them; their pages still looked right.

A site may refuse the request. Some answer anything that is not a full browser, or Cloudflare's network, with an error: during testing in October 2026, w3.org answered Recolor's fetcher with 403, and news.ycombinator.com now and then answers with 419. The card then says the site refused and gives the status; saving the page and uploading it is the way around.

Other reasons are Recolor's own limits: more than 5 MB of HTML, no answer within 10 seconds, an address on a local or private network, a page behind a login, or a file that is not HTML. Each has its own message, listed on Loading a page, and the numbers are on Limits.

The preview is a sandboxed frame with no origin of its own, which keeps the page's scripts away from Recolor and from you. Most pages do not mind. Some do:

• Module scripts from another domain need permission (CORS) that a frame without an origin does not get, so they do not run. On developer.mozilla.org, astro.build and vite.dev this left parts drawn by script empty.
• Scripts that build addresses from the page's origin can throw, since the origin is "null". GitHub's did, with nothing visible as a result.
• Pages built entirely in the browser need their scripts; with scripts off they may show little.

The Scripts switch is the lever: off shows the HTML and CSS the server sent, which often carries the colors well. Nothing a page's script does reaches the site, its owner or your accounts; What Recolor stores and fetches covers the sandbox.

The matrix runs in headless Chrome against Recolor's development server. For every site and both Scripts settings it records the time from opening the app to the engine's report, the engine's own reading time, the colors found, the share of elements a palette changes, and a fidelity check that compares every element's computed colors before and right after the engine's rewrite. Screenshots in the page's own colors and in three palettes are looked at by eye. The engine read the largest page, github.com with 28,104 declarations, in 337 ms.