By Mark Rosewater

https://magic.wizards.com/en/articles/archive/making-magic/mechanical-color-pie-2021-changes-2021-10-18

One blatant disagreement I have is how green is now secondary in animating artifacts. Where Green philosophically hates artifacts, but now is an enabler? Even though all these years, Tezzeret, who is blue-black, is one of the most popular methods of animate artifacts strategies. If not black, then red should be considered since it loves to tinker with artifacts. Even white may be more likely than green, both philosophically and mechanically (who loves equipment). He also omitted artifacts animating other artifacts (for that matter, entire article neglects where colorless and artifact partake in the mechanical pie.)

I assume that's more a reference to what colors have gotten that ability historically rather than a new addition (unless we're going to get asurprise soon???). Titania's Song and Lifecraft Awakening mean that this is accurate. Green is indeed the next best color to animate artifacts. No mention of black for Xenic Poltergeist though.

The color pie does cover colors. Colorless is not a color. Simple as that.

Mono black = 3 (1 old)
Mono green = 2 (1 old)
Mono white = 2
Mono red = 3 (mainly vehicles)
U/B = 3
U/G = 1
U/W = 1
WUB = 1

Black has a clear lead over other nonblue colors in terms of animating artifacts.

Green has a card that is an exception in an artifact-flavored set. Which is frankly less flavorful than an old black card (also from artifact set).

White also has more recent animate artifact cards than green. Moreover, white and red can reanimate artifacts (and by extension, artifact creatures).

Technically black isn't a real color because it's the absence of color. Doesn't make black less important in our lives.

Freezing lands didn't work for red (not surprising). Instead, such anti-land control/tempo could be focused on blue/green. To enable soft-lock prison decks, in the same veins as Turbofog and Stasis.

Considering the small numbers itwould be useful to the discussion to actually list the cards (as I did) to help me understand the situation e. g. I specifically did not count cards that only animate Vehicles due to the special situation of Vehicles, but of the five cards I reviewed for black none fulfilled the animation criteria.

I didn't find any of the hybrid cards you mention.

Black is not the absence of color. You probably mean the absence of (visible) light.

I have given you the reason colorless is not covered in the color pie. If you want to argue the reasons, you should goto the person who determines them, not me.