[nostoc]

No, a blue filter, like a blue plastic bag would let blue pass and absorbe the other colors. That's why if you shine a white light through a blue filter, things look blue on the other side.

Now, some of the blue light is scattered away, and that's why you see the plastic bag itself as blue.

[Nition]

Hang on, so if you shine a white light through a blue filter, the light on the other side looks blue. And the filter itself still looks blue on both sides. But then, where did the non-blue component of the light go?

[simcop2387]

Converted to heat. What's going on here is a discussion about transmission and transmittance. [1]

[1] https://www.swiftglass.com/blog/key-differences-transmission...

[lgats]

Imagine looking at this blue-transparent bag with a red light, it will appear more opaque.

[ganzuul]

Just like laser light protection goggles.