I have used Rosco #27 Medium Red. For example, this is what I cover my flashlight with. I also have it over the bulbs that illuminate the color wheels on my enlarger head. My local shop carries this color, but not Rubylith. Your #25 filter should work also.

Why are enlarger safe filters red? Because this makes them safe for nearly all B&W papers.
Why are safelights frequently orange? The orange light looks brighter to the human eye, but not all papers are safe to an orange light.