Sorry, this will probably be tl; dr....I'm procrastinating again from something else I should be doing, but here goes:
My background is neuroscience, not fisheries biology, but I can add a little about principles of vertebrate color vision. Most of what we know comes from work on humans and other mammals, although all vertebrate visual systems follow the same principles (yes, with many variations in parts and tuning, but the same basic rules are followed everywhere).
The first thing to understand is that color is your brain's way of telling the difference between different wavelengths of light. We cannot know how bass experience color subjectively...but by exactly the same logic, I cannot know how you experience color subjectively either. However we can find out how well non-humans like bass can distinguish between differently-colored stimuli the same way we can with humans: Get them to make different responses for different colors.
So it's not helpful to get hung up over what bass "see"...let's worry about what they can detect and what they can distinguish, both of which can be determined from behavior in visual discrimination experiments: Train the fish to select a visual target in order to receive a reward (or avoid a shock). Then, test whether they can tell the difference between the rewarded target vs. a different one by giving them a choice.
A good example is this recent study, which has generated some discussion on these boards and elsewhere (freely-available study, no subscription needed -- hooray for open-access publishing!):
https://academic.oup.com/cz/article/65/1/43/4924236
This study found that bass easily detect and discriminate red & green (or more precisely, reflected light off objects that we see as red and green), but have difficulty telling the difference between blue and black, and between chartreuse-yellow and white. The same thing has been suggested repeatedly by prior studies, although this one upped the ante by testing both visual choice behavior, and light-sensitivity of cells in the actual eye tissue upon dissection.
How can we make sense of this?
All animals with visual systems have a light-sensitive cells in the eye that are tuned optimally to detect particular light wavelengths (with a smooth drop-off above and below that optimal wavelength -- giving the cell a range that it is most sensitive to). A single such cell supports the ability to detect the degree of light shining onto it, with a wavelength falling within its sensitive range.
Most vertebrates have two types of cells that do this: Rods, which are tuned to a broad range and support low-light, but monochrome (black and white) vision, and cones, which are tuned to narrow ranges. Rods can tell us about the level of light, but not color. It is the cones that support color vision because their narrow ranges make them sensitive to only some wavelengths and not others. Species frequently differ in how many different cones they have. If you had just one type of cone, that wouldn't do much. You'd see differences in light intensity, but you wouldn't tell the difference between high vs. low wavelengths.
But if you have two cones tuned to different wavelengths, that gives you some ability to distinguish wavelengths from each other: Say, a "high" wavelength cell and a "low" wavelength cell. They would give unequal responses depending on what the wavelength is, and if the cones give different responses, you now have enough information to support a perceptual difference between colors. Essentially, the difference between the responses of the two cones is a color signal; the difference can be large or small, and can go in one direction or another...you have a range of responses that reflect a range of wavelengths, as long as those wavelengths fall within the sensitive ranges of the cones.
There is one wrinkle though: The two cones would give the same response under two situations: (1) there is more than one wavelength of light present, thus stimulating both cones, or (2) there is one wavelength falling directly between the two cones' peak sensitivities, where the ranges overlap and stimulating the two cones equally. Because these two situations result in the same response of both cones, the color signal is identical, meaning there is no way to tell the difference between the two. However, with three cones rather than two, this difference can be resolved, because three cones support an additional color signal beyond that supported by two cones.
And this is the key to understanding the findings of the study linked above: the results are consistent with bass having two types of cones, whereas humans have three.
In humans, long wavelengths generate a perception of red, medium generate green, and short generate blue. White is based stimulation of all three at once. Yellow is based on about equal stimulation long and medium, but both greater than short. The human visual system calculates two signals based on wavelength detection: Long vs Medium and (Long+Medium) vs. Short. Perception of red and green is based on the first signal, while perception of blue and yellow is based on the second signal. The distinction between these signals is the basis for color afterimages: staring at something red for about 30 seconds or more gives you a green afterimage (and vice-versa) when you shift your gaze. The same is true of blue and yellow as a pair. It is also the reason why the most common kind of colorblindness affects red and green selectively -- most people who are colorblind are "red-green colorblind", where they see color, but have difficulty telling the difference between red and green.....this is a selective dysfunction in the first of the two signals.
In bass however, the experimental evidence suggests they have the first of these two signals, but not the second. They have two cones with maximum sensitivity at similar wavelengths as our long and medium cones, giving them good recognition of red and green. However, in a two-cone system like this, yellow and white should produce the same response (high response out of both cones), and blue and black should produce the same response (low response out of both cones). That is a prediction that falls naturally out of this kind of 2-cone system, and the study cited above verified that prediction by experiment for largemouth bass.
So what about your lures? In the study cited above, and others like it, the intensity of light reflectance was held constant for the purpose of control. Of course, your actual lures do not reflect light at the same intensity. Bass can of course detect differences in intensity, even when they cannot detect differences between two wavelengths. I don't have a citation in front of me, but I recall encountering evidence bass have very good "twilight" vision, supported by very sensitive rod cells. That same sensitivity would apply to subtle distinctions in intensity, as long as the environment is not too bright.
In many cases, I suspect that when anglers feel bass are distinguishing between subtle differences in color (beyond variations of reds and greens, perhaps), what may really be going on is the bass are responding to intensity: levels of overall "bright" vs. "dark". Many versions of Black & Blue, for instance, may simply be "Dark, but some variation in how dark it is". Also, some variations of chartreuse may be more greenish than yellow, creating a distinction from white. And many baits that look otherwise similar, may differ in degree of contrast between light and dark; bass may be especially attentive to countershading contrasts, for instance. All this is to say, in actual lures, a color difference may not actually be about color itself.