Paul G. Hewitt has a great non-mathy description of this in his book Conceptual Physics.
Strike a tuning fork and it vibrates at a characteristic frequency, its Natural Frequency. The tuning fork might put out other frequencies but they are dampened faster than the target frequency. Dampening sucks energy out of vibration and becomes thermal if it doesn't become sound.
You can think of many things as being made up of tiny tuning forks. So hitting a metal sounds different from hitting wood.
Thes stiffness of a spring can determine the frequency of its vibrations. Again it has a natural frequency.
Like these examples, you can think of atoms and molecules as tiny optical tuning forks that re-emit some of the light and absorb the rest. Some light passes through.
The color you see depends on various features of the atomic and molecular interactions. For example, how strongly bounded an electron is to its parent atom is roughly analogous to the stiffness of a spring.
Vibrations in general can often be approximated through the analysis of Simple Harmonic Motion.
This is why Planck was able to analyze the interaction of Black Body Radiation with matter by assuming the radiation interacting with tiny "Harmonic Oscillators" in the surface of the black body.