**Core Concept**
Color vision is a complex process involving the interaction of multiple types of photoreceptors in the retina, which ultimately allows us to perceive a wide range of colors. This process is mediated by specialized cells called cone photoreceptors, which are sensitive to different wavelengths of light, and are responsible for transmitting color information to the brain.

**Why the Correct Answer is Right**
The process of color vision involves the activation of different types of cone photoreceptors, which are sensitive to different wavelengths of light (red, green, and blue). However, the actual perception of color is not simply a matter of combining the signals from these different types of cones. Instead, it involves the interaction of these signals with specialized cells called opponent color cells, which are responsible for detecting the differences between colors. These opponent color cells are sensitive to specific combinations of cone signals, such as red vs. green, and are responsible for transmitting color information to the brain. This is why the correct answer is C. Involves opponent color cells.

**Why Each Wrong Option is Incorrect**
**Option A:** Independent of wavelength of light - Color vision is actually dependent on the wavelength of light, as different wavelengths are detected by different types of cone photoreceptors.

**Option B:** Depends on intensity discrimination - While intensity discrimination is an important aspect of vision, it is not directly related to color vision, which is primarily mediated by the interaction of cone signals.

**Option D:** Minimum at fixation point - Color vision is actually optimal at the fovea, which is the area of the retina responsible for central vision, and is located at the fixation point.

**Clinical Pearl / High-Yield Fact**
One important aspect of color vision to remember is that it is mediated by the interaction of multiple types of cone photoreceptors, and is not simply a matter of detecting the presence or absence of light. This is why conditions that affect the cone photoreceptors, such as age-related macular degeneration, can lead to significant impairments in color vision.

✓ Correct Answer: C. Involves opponent color cells