I'm going to be a senior in high school and I've found philosophy podcasts to be a great way to sample the thoughts of famous philosophers without having to drudge through esoteric forests of essays. Between listening to Philosophy Bites and Nigel Wharburton's reading of his book Philosophy: The Classics, I've become familiar with a bit of Hume and Kant. It is probable that I have misunderstood much of the material of the podcasts, so the material of this question does not reflect in any way the reliability of the sources.
As I understand, Hume proposed the a priori and the a posteriori, the latter constructed by experience. Kant then respected the two categories but divided them into analytic a priori, synthetic a priori (new after Hume), and synthetic a posteriori. What interests me is the problem of "the missing shade of blue." Because all ideas originate from experience, even simple ones like fundamental colors (or shades of them), then are not all colors a posteriori? For they cannot be a priori in the instance of a blind man.
To reconcile the problem of whether one can imagine a missing shade of a color wheel, and furthermore define the means by which he may do this, might Kant have had an opportunity to further classify and suggest that experienced colors belong to the category of an 'analytic a posteriori' and imagined colors belong to the synthetic a posteriori (because they are 'produced' from the relations between two experienced impressions)?