Ah dang, I forgot to re-set the temporary variable in that popup. That's my bad!
Essentially, instead of listing all options with <<option "the-option">>, I used <<optionfrom "_variable">>, but forgot to set the variable before that.
If you check the CC-Eye passage (which is almost the same passage but not in a popup), there is this line at the start:
<<set _eyecolours = ["white", "grey", "golden", "green", "blue", "maroon", "brown", "black", "red", "pink", "purple", "lime", "seafoam", "cream"]>>
(it's the line that make the cycle work!)
BTW: if you are looking for explanation on how the Cycle macro works, check out this guide!