Yellow lights do not kill bugs.
Yellow lights do not repel bugs.
However...and this is important...Yellow bug lights attract far fewer bugs...than white lights...and that is a fact.
Flying insects and many other bugs that can be pests...are attracted to those white lights in your yard or attached to the house that you let burn all night for safety reasons.
The brighter the white lights the more bugs are attracted.
The more bugs you attract, the more food you are providing for the pests...ants, roaches, frogs, spiders, more spiders, and more spiders.
By turning down the intensity of those white lights or shutting the light off altogether, you decrease the number of bugs that will be available for supper for the those bad pests you don't want living nearby.
But how about those yellow bug lights?
Are yellow bug lights effective?
Should you buy yellow bug lights?
Insects and humans see lights differently. Because of this we can better control bugs at night by adjusting the color of lighting the bugs see.
We see colors best from deep blue to dark red. Flying insects see lights that radiate ultraviolet energy (so called black lights) and blue lights best and lights with less ultraviolet and blue are not as visible to the insects. Insects see black light fluorescent, mercury, and metal halide best.
Lamps which insects have a difficult time seeing include incandescent, high-pressure sodium, and the bug light that is an incandescent yellow.
So the answer is yes. Bug lights work.
And if you want to get rid of bugs and insects and whatevers, install that yellow glow bug light and you will attract less food to the table for your pest population. That means less pests in your home. And that is good.