From the sounds of the BFI’s write-up, the 1924 film’s always been tinted and that’s what the restoration fixed. (If you look at the clip on Youtube, you’ll see it’s not “colourized” like the still image in the BB post, but rather a single colour across the entire frame.)
It was not uncommon for silent films to be tinted* and toned** — at its peak in the early 1920s, possibly as high as 90% of the films released per year contained at least some colour — and restoring them to the correct colour is actually a fairly difficult & involved process. Many copies of them didn’t preserve the colour, and those that did often reproduced colours that had already started to degrade.
* The developed film gets placed in a dye bath. The colour winds up in the highlights.
** The silver in the film is actively replaced. The colour winds up in the shadows.
