Me neither, which is another reason why it probably could have been clarified. I simply used the codes on the pencils, so I'm guessing they're a Stabilo scale/standard.

I realized I should have clarified that. Those numbers correspond to the color codes, because the lighting on the photograph is not entirely accurate (some people commented on the dark blue, which is actually more purple in reality).

It's easy to calculate the volume of 'pencil core' that was consumed, but I have no idea how that correlates with the actual surface area...

I'm not sure if you meant that as a joke but yes, I asked him to line up the pencils ;)

This is a valid point I hadn't considered. The 'darker blue' is actually more purple in normal lighting (that's what he calls it, too). However, the same thing applies to the greens.

Here is a recent drawing of a rainbow, featuring the brown paper. He usually includes black in the rainbow, but in this case I believe the darker stuff is purple.
https://imgur.com/a/vRrYt6G

The pencil info is in the image. I can definitely recommend them for this age range. They're massive, won't ever break, and above all have superb color saturation. They're pretty high on the 'waxy' end. Not cheap I guess.

There is obviously a lot of uncertainty in this dataset. For example it's entirely possible one pencil may simply have rolled off the table at one point in these 3 years and be forgotten hidden under the couch for weeks.

I do all the sharpening. Unlike regular pencils however, you can keep using these even when the point is more or less flat, due to its large size. Though it feels painful to watch, my toddler doesn't seem to be bothered by flat tips at all...

One might assume children prefer colorful things, but in this case, black and white are clear winners throughout. Overall less variance than expected. The 880/810 'gold' color sucks and is poorly visible on (often used) brown paper.

Data sourced directly from my toddler's colored pencils. Used with Adobe Illustrator

edit: Thanks for all your comments.

• For those who commented on the Berlin-Kay color theory/appearance in language, that's super interesting. I love this sub!
• For the OCD people who feel offended with the poor ordering of the pencils by length: you can take that up with my toddler.
• Special mention for u/tonybenwhite who took the effort to calculate the colored surface area