There is no exact color of things.

Colors of objects depends on the wavelengths of light emitted by objects and the interpretations of those wavelengths by eyes and brains.

Point 1.

Light wavelengths are real, but colors are interpretations of eyes and brains.

Light comes in a wide range of wavelengths. Human eyes see wavelengths between 400 and 700 nanometers. Bees see light from 200 to 600 nanometers. See the third image on this page.

Different wavelengths of light stimulate cones in the eyes of human and bees. This stimulation is interpreted by the human and bee brains as colors.

Look at the image on this page. The top row is how these flowers look to humans. The bottom row is how the same flowers look in ultraviolet which bees can see.

So which is the "real" color of the flowers? What humans see? Or what bees see?

Point 2.

Your point that the wavelengths of light shone on objects changes the wavelengths of light reflected off objects that reaches our eyes.

Point 3.

As objects get hot, they can emit more than reflected light, and start emitting their own light at different wavelengths depending on how hot they are. This called black body radiation.

Look at image on this page. Near the center of the image is the vertical rainbow showing where the visible light our eyes can see is. At room temperature, 294° kelvin, objects are emitting wavelengths of reflected light that we can see with our eyes.

As objects, e.g., piece of metal, heat up to say 3000° Kelvin, objects glow red because the strongest wavelengths of visible light are at the red end. At 6000° Kelvin, objects glow white because wavelengths of visible light are equal across across all visible light spectrum. At 10000° Kelvin, objects appear blue because the strongest wavelengths of visible light are at that end of the spectrum.