Well, light can be modeled as either a wave or a particle[1]. When talking about colors, it makes more sense to talk about light using the wave model of light than the particle model of light--not that either way of talking about it is wrong, it's just that the particle model is way more complicated for modeling this particular phenomena.
> "red light" is the photon as well - ie a photon with wavelength between 620-750nm
No. If you're talking about wavelength you should be using the wave model. It absolutely makes sense to say "red light" when you're talking about a wave.
There's no such thing as a red photon because photons don't have color by themselves--red light is made up of many photons, which have a frequency.
It sounds like your argument is basically that you don't know how to represent color with the particle model of light, so you assume the answer is "the mind". Not only can you go learn how to represent color using the particle model, but even if that weren't possible, assuming that anything you don't understand is "the mind" is pretty premature.
> In a sense, you are claiming that this chemical cascade is 2 things: 1: a chemical cascade and 2: the perception of red (i.e. the subjective sensation of looking at red); whereas, I would say the chemical cascade is just a chemical cascade... that's all it is, because of course chemicals can't be chemicals AND sense perceptions - that's the real incorrect leap of faith in your argument.
People who have the chemical cascade experience red. People who don't, don't--even if red light is there (i.e. if they are colorblind). Do you have any reason for believing these are different phenomena?
> You say that I have yet to present an observable phenomenon that is clearly in the mind, but just imagine a red triangle, boom there you have it - that red triangle only exists in the mind. [...]
> If you still disagree with this, tell me where is the red triangle?
It's also in the brain, because the mind is just the brain.
This isn't hypothetical. We can read (very) fuzzy images from people's brains using neural-imaging[2]. I'm not aware of any experiments that specifically has read a red triangle, but I don't see any reason to believe that this image is uniquely in the mind and not the brain.
Again, it seems like you're just defining "the mind" as anything that happens in the brain where you don't know how it happens. And again I'll say, even if we didn't already know how it happens, concluding that this is "the mind" rather than some physical process we haven't yet discovered, is premature.
> it's simply made of qualitatively different material than the brain.
If it's qualitatively different, what are the qualitative differences?
As for the parts of your post I didn't respond to directly: declaring things irreducible, patently absurd, and declaring that you know things, all ex nihilo, is not a persuasive argument.
[1] https://en.wikipedia.org/wiki/Wave%E2%80%93particle_duality
