Rewrite rule for colon

I have an existing blog with URLs /tag/XXX and /page/XXX and I can’t seem to create routing rules in Grav to route /tag/XXX to /tag:XXX. How can I do this?

I should also say that redirects work. But I specifically want to maintain the existing URLs.

Taxonomy pages are special, as the tag name is a parameter. I don’t think there’s an alternative to using a redirect.