The plugin hyprchroma is outdated and does not build against the latest (non -git) build of Hyprland, v0.51.1 at the time of writing this issue. The latest Hyprland version supported by the plugin is v0.46.2. Furthermore, the project may be abandoned, since the last changes were committed 8 months ago and issues are disabled in the repository.
There are also several forks of this plugin, but all of them are outdated as well.
It might be a good idea to add a warning for the plugin to let other users know that it probably won’t work with newer versions of Hyprland.