I am also not a fan of the animations and blinking happening in the background. It makes me nauseas. The first thing I do is turn it off. With the added script, the browser will now remember the changes, but this won't apply to Tor if used with the highest security features, will it?
Usually websites also save Dark/Light themes and other preferences in browser localStorage.
If the default splash theme is considered light, can you imagine what a dark one would look like.

The exchange is quite good. With more liquidity and lower fees it would be close to excellent.