This is actually really cool, in terms of just literary analysis. If you're the first person to put up a visualization on colors in songs/albums like this then definite ultramega kudos -- and I think albums might be even better than songs for comparing across artists and careers.

To critique the visualization itself, I feel like there is a better way to show the evolution of a set over time that doesn't feel like they're all kind of in their own little corner, independent, on a white background (which makes the grey hard to see btw). If the emphasis is indeed on evolution, or perhaps a fan might, knowing Swift's bio, coordinate the use of colors to her perceived emotional state, then placing the colors vertically and connecting them smoothly along a horizontal time axis like a rainbow of thickening and thinning bands might work. Just a thought -- I'm sure you or others will have better ideas.

And good job of course for including the citation information on the image itself. (I'd recommend including a year or date or backlink, though, which helps people find your original post if they want.)

i think my favourite discovery may have been the FOURTH pen type - the permanent marker revenge song 😆