I'm guessing that maybe most colors I see are a mixture of CMYK or something alike, but if my eye can't tell the difference, does making something only reflect a single frequency instead, matter for somebody looking at an object?
Most useful compounds, even alloys, of only metallic elements, tend to be composed of MAINLY two metals. (usually they are 2 main ones plus many lesser metals) This one is composed of THREE and isnt even a metal.
The significance is mainly due to better durability [2]:
> the increased UV absorbance and stability in outdoor weathering and heat buildup tests demonstrate that YInMn blue is superior to Cobalt Blue
[1] https://www.sciencedirect.com/science/article/abs/pii/S01437...
[2] https://chemistry.oregonstate.edu/content/story-yinmn-blue
By mixing, you can reach any color within the triangle — but you can‘t leave it, as then you‘d have to start from an even "bluer" blue.
This is basically what the new pigment enables, and not just that: This shade seems to be way more color stable over time. All colors fade eventually (especially with UV irradiation), so if you want to preserve the original color in a painting for example, this matters.