Why are some solutions seen by the human eye with specific colors, while other solutions are observed to be colorless??
I am not certain of your question.
The first thing to note is in the dark, they do not have color.
The second thing to note, and ask, does the color of the solution change when radiated with different wavelengths of light?
The color you see coming from the solution can be light that is reflected, or diffused, or re-radiation of energy which impinged at a different wavelength.
On the diffusion of light, remember that short wavelength (such as blue) are "bent" or diffused more than the reds.
Remember, many elements have d-orbitals that are sensitive to specify impinging wavelength..if the electrons are excited, when they return to ground state, they can appear to emit light. Transition elements in solution are often in this category.
The answers to your question are complex, and you really should ask it about specific solutes. Life is generally not simple.
The color of a solution is determined by the presence of certain substances called chromophores, which can absorb specific wavelengths of light. When a solution contains chromophores that absorb light in the visible spectrum, it will appear colored. If a solution does not contain any chromophores, it will appear colorless.
To understand why certain solutions have specific colors while others are colorless, it can be helpful to consider the interaction between light and molecules. When light passes through a solution, it interacts with the molecules present. If the solution contains chromophores that can absorb certain wavelengths of light, those wavelengths will be selectively absorbed by the chromophores. The remaining wavelengths will be transmitted or scattered, giving rise to the observed color.
For example, a solution containing a chromophore that absorbs red light will appear green or blue. This is because the chromophore absorbs most of the red light, but transmits or scatters the green or blue wavelengths, which our eyes perceive as the color of the solution.
On the other hand, a colorless solution indicates the absence of chromophores that can absorb visible light. Without any chromophores to selectively absorb specific wavelengths, all colors of light are transmitted or scattered equally, resulting in a colorless appearance.
It is worth noting that even though a solution may appear colorless to the human eye, it may still contain molecules or particles that absorb light in other parts of the electromagnetic spectrum, such as ultraviolet or infrared light. In such cases, specialized equipment would be needed to detect and analyze the presence of those chromophores.