Hey, this is something we tried to achieve and for long time we kept researching , unfortunately we do not see this as a standard option at all and can not be achieved without a 3rd party app. There a couple of decent applications who can do this by grouping different products as variants i.e. you create a blue tshirt and red tshirt as separate products then use the app to combine them as variants. This way you have 2 products displayed and both display the color variants without messing up with you SKU count
Hope this helps