Most of this forum’s user interface elements are light gray on a white background, which provides insufficient contrast for users with visual impairments, and fails to meet WCAG standards for web site accessibility.
Also, on the forum’s home page, the category descriptions are also printed in very light gray small text on a pure white background. This too fails to meet accessibility standards. And when viewing the individual categories, threads that have already been viewed are also displayed in extremely light gray and barely visible text.
I noticed that Memrise is using Discourse as a hosted service, so I don’t know if this is a standard discourse theme, or if Memrise “designers” customized it to be this way.
Either way, it is a major design failure, and fixing it should be a priority.
Deploying the site in this condition indicates a troubling lack of concern for making the site accessible to the visually impaired.