With all the lighting off a darkroom should be just that - dark. Not quite dark, not very dark but completely dark, you shouldn't be able to see anything at all.
As a simple check here is what to do.
Turn off all the lights in your darkroom, including any safelighting, but leave lights in adjacent rooms on. Shut yourself in for at least 5 to 10 minutes. Don't stand with your eyes shut otherwise when you open them it will appear to be dark. Let your eyes adjust to the darkness for several minutes then look for light leaks around door and window frames or any other openings into the darkroom. Make a note of any you find and get them covered up.
Materials for blacking out rooms are available from photographic/darkroom suppliers and DIY stores.
When you are done check it again.
Don't seal yourself into a darkroom as you will require adequate ventilation while working with photographic chemicals as well as air, unless you want to suffocate.
Now that you have got your darkroom dark you want it bright enough to see what you are doing. You do not have to paint your walls black !! As the only light in your darkroom will now be coming from your , probably quite dim, safelight your walls can be white to make most use of the safelighting that is available. It is, however, a good idea to paint the wall and ceiling directly above, behind and beside, if next to a wall, matt black. You may be surprised at the amount of light that can leak out of an enlarger head.
Now for the bad news. Contrary to popular belief safelighting is not actually safe.