MTGNexus

Fractal Blade (Uncommon)
0
Artifact — Equipment
Spectra — Equipped creature gets +X/+X, where X is the number of colors among cards in your graveyard.
Equip X

Will the equip cost recognize the value of X from the previous rules text or does it need to be explicitly restated?

You need to define what X represents for the Equip ability. Those abilities aren't linked and there's no rules basis for the Equip ability reading the other ability's X value.

Thanks. Should I use Y instead of the second X? How about for the following where I don't want the X's to be the same.

Recombinant Wurm (Mythic)
X
Artifact Creature - Wurm
0/0
Armed X (This creature enters the battlefield equipped with X colorless artifact Equipment tokens. Each has "Equip 1" and "Equipped creature gets +1/+1.")
X: Move target Equipment you control with converted mana cost X to target creature you control.

If you want multiple different variables you should use Y, the rules won't fall apart if you use multiple Xs but it is needlessly confusing.

The rules that define what's going on are
107.3h Normally, all instances of X on an object have the same value at any given time.
107.3m Some objects use the letter Y in addition to the letter X. Y follows the same rules as X.

107.3i-k detail exceptions to 107.3h so if you use multiple Xs you would just add an additional exception.