Steve is right. Also, I've seen the paint slowly come off, creating 'unsafe' lighting. The purpose of a safelight is to protect your paper for as long as possible. No safelight does that 100%, but typically, a good safelight protects for 20-30 minutes against fogging. To be sure if a simple and inexpensive light works, one needs to test.

I can offer a free chapter from our book which explains the test in detail:

If you want to keep it simple, start with the coin test on the last page.