Hello,
Please navigate to Dashboard -> Products -> Attributes -> Color -> Configure iterms, enable swatch as shown http://prntscr.com/jskm29
Navigate to Theme Settings > Shop > Attribute swatches > choose pa_color (your color attribute), if you want to show the attribute on the product grid, and enable “Use images from product variations” if you want to show variation images instead of colors.
Make sure each variation in a variable product has an image: http://prntscr.com/kk870w
As soon as you create attributes and items and add the attributes to the products, a filter would work.
Best Regards