Allow indexing for eCom filters? (SEO)

I’m looking to noindex most filters on my product category pages (collections) as most of them aren’t keywords that people would search organically.

However, certain filters have keywords associated with them that do have search volume. Other than creating more collections, am I able to selectively enable these filters to be indexable, whilst leaving most others as noindexed?

For example, the collection is T-shirts. For argument’s sake, I don’t want to create a new collection for White T-shirts, I want to enable the filter for Colour: White to be indexed by Google, therefore creating a searchable page. How do I got about allowing for this, whilst also not allowing the filter Sleeve Length: Long to be indexed?

As an additional bonus points question: How can two filters applied, i.e. Long Sleeve White T-shirts be canonicalised to the filter page White T-shirts?

Any help is appreciated! Thank you!