Variants and product families
A product sold in several colours or sizes counts as one product. It appears once, as the variant Amazon showed most, and its numbers cover the whole family.
A single Amazon product often exists as a dozen ASINs: one per colour, size or pack. They share a listing, share reviews, and compete as one thing. JustRanks treats them that way.
What you see
The results show each family once, as the variant that was most visible in the selected period, with its title, image and price. The numbers on it (position, visibility, coverage, the JustRanks Score) belong to the whole family. If Amazon showed more than one variant, a chip such as "+3 variants" opens the Variants tab of the drilldown: which variant Amazon showed, overall and on each keyword.
Comparisons work on families: the movement view has one row per family, a head-to-head takes one listing per family, and marking one variant as your product marks all of its variants. A note on a product belongs to the whole family, too.
Why not simply the parent ASIN
Amazon does not publish the parent ASIN in search results. What appears is one variant, chosen by Amazon for that search, and Amazon swaps it. A family can be shown as its blue variant this week and its red one next week.
Taken at face value, that swap looks like one product disappearing and another appearing: a competitor's history would break in half, and your coverage would drop for reasons that have nothing to do with your ranking. JustRanks therefore resolves every variant to its family and counts each placement for the family, whichever variant Amazon showed.
How families are found
A product's family comes from its product page, which lists all of its variants. JustRanks looks families up when a keyword is first searched or saved in a market, and keeps them current as new products appear on the page. Families are refreshed from time to time, so variants added to a listing later are picked up.
Until a product's family is known, it counts as a product of its own. That mostly affects keywords that are new to the database and products that have only just appeared on a page.