Product Variant confusion

Hello, I have a similar product variant problem and are having trouble understanding them.

I used the feed template from nopadmin, added all my data. On the Product Variants column I have some products that have more than one variant i.e.

a wheel chair available in blue, red, silver, purple.

so naturally i then put their id's with ; in the spreadsheet.

Once i imported the feed instead of creating a different line for each of the variants belonging to this product it just creates one entry and titles it like this wheelchair blue;wheelchair red etc?

I would have thought it works in the same way as the categories where you list where you want the product to be categorised and if there is more than one category you put a ; between it.

can you help with my confusion? also is this the best way to do this or should these be done under Cross sells instead?

many thanks

MK