To make a photo-like satellite image, you need red, green, and blue wavelengths of light.

"This could theoretically produce a peak of the spectrum in the green wavelengths."

It's green because its scatters the green wavelengths of light back at our eye, while absorbing the rest.

Instead frequency doubling can be used to provide the green wavelengths.

The red, yellow, and green wavelengths of sunlight are absorbed by water molecules in the ocean.

For example, a blue light filter appears blue because it absorbs red and green wavelengths.

If white light is shone through the filter, the light transmitted also appears blue because of the absorption of the red and green wavelengths.

Most of these produce light in the green wavelengths, although a few blue-emitting species have also been discovered.

If your yellow object is really emitting red and green wavelengths, it will look dark when viewed through the yellow filter.

Behind the gauge body are light sources with two quite different wavelengths, typically red and green.