Printful API Expert Needed – Bulk Remove Color Variants From ~2,000 Products

I am looking for someone experienced with the Printful API and Shopify integrations to help clean up approximately 2,000 Printful products.

Currently, most of my T-shirt designs have multiple color variants. I want to modify the products so that only the Black color remains for each design, while keeping all available sizes for Black.

For example:

Current:

Black – S, M, L, XL, 2XL
White – S, M, L, XL, 2XL
Navy – S, M, L, XL, 2XL
Red – S, M, L, XL, 2XL

Desired:

Black – S, M, L, XL, 2XL

The products are connected between Printful and Shopify, and I am okay with the corresponding Shopify variants being removed as part of the process.

Requirements:

Experience with the Printful API
Experience with Printful/Shopify product synchronization
Ability to process approximately 2,000 products efficiently
Remove all non-Black color variants
Keep ALL Black size variants
Do not delete an entire product if it does not contain a Black variant
Test the process on a small number of products before applying it to the entire catalog
Verify that Printful and Shopify remain properly synchronized afterward
Follow Printful API rate limits and avoid disrupting the store

This should preferably be done through automation/API rather than manually editing thousands of products.