Spreadr app does not import product variants / options (sizes, colors etc).
Most of the leading affiliate stores do not display variants. They only show primary product and leave the variants, shipping details etc to the destination site. Examples - canopy.com, thisiswhyimbroke.com, thegatdgetflow.com, lyst.com.
This is done primarily to get the affiliate 'click' and redirect the user to the destination site. Once the visitor is on destination site (Amazon in our case) you get commissions for any variant they buy - not just the ones you promote and link out to. Not only that, you make money if users purchase anything else from Amazon.
Moreover, importing variants significantly increases the time required to import products and introduces complexities in auto-syncing.