Allow any value for product attribute

I developed a site for a client which has bespoke products with a vast number of colour options (~270). To save the client adding every single colour to each product I set up a special tag, [All Colours], and added that as a term for the multiple attributes. I then converted this on the front end of the site to pull in all of those colours for a customer to choose. It would then attach the colour to order as metadata so that the administrator knew what the customer had selected.

Since updating WooCommerce (on a development site) this no longer works as text attributes have been removed. I’m assuming it’s no longer working because the site needs to see ‘[All Colours]’ as a value for each attribute rather than the selected colour?

I’m trying to figure out the best way to tackle this issue on the latest version of WooCommerce so that administrator doesn’t need to select each colour individually* and the customer can still select from all the colour options. If there was a way to allow any value to be added as attribute metadata that would solve the issue but it doesn’t look like that’s possible any more? Are there any other solutions out there to allow this?

To summarise:

• A customer can select from 270 colours.
• An administrator can assign colour groups to attributes when adding a product.

Any help would be greatly appreciated.

*Unfortunately using the ‘Select All’ won’t work as there are a number of different colour groups that can be assigned to a product/attribute.