Variants count towards bulk price amount

[sean_nwfs]

We are going to be selling a product that comes in two variants but we want either variant to count towards the parents total amount purchased so a bulk price can be calculated. So if someone is buying any sweater, whether it is red or blue, and if they buy a combined total of 10 or more they get the bulk order price (4 red and 8 blue = 12 sweaters).  Is there a way to set this up?  Sorry if this is totally obvious.

Here is our catalog: https://www.symptopro.org/catalog.html. Note that I don't have the item listed yet since I don't want to publish it until I get this scenario figured out.

We are on VirtueMart 3.0.18 & Joomla 3.6.4
PHP: 5.6.28