You included the snippet swatch.liquid with the name of a product option — 'Colour'
— that does not belong to your product.
Use {% include 'pro-color-swatch' with 'name of your product option here' %}
Example: {% include 'pro-color-swatch' with 'Colour' %}
This is case-sensitive! Do not put in 'color'
if your product option name is 'Color'
.