Hi
I checked your brief.
Question: Do you upload product colour swatch images / hex code of colours to your variation or you enter color names as variation attributes? In case you enter color names, I will need to first code so that you are able to enter the hex code of the colours with your attributes.
Once that is done coding the colour swatches to display on your products listing page is easy as I need to just loop through the color variation, get the colour hex for the products and show the swatches in HTML
I will need the wordpress admin area access as an administrator and the FTP to your server to complete the required coding.
Let me know if you have any questions for me.,
Regards,
Pinaki