Hi,
you can change the ordering of the values of the characteristic when you edit it via the menu Products>Characteristics.
Like Nicolas said : You need to edit a characteristic to change the order of his values.
And in the product page, it is possible to sort the characteristics.
There was an missing image in the package but I just fix it ; so you can redownload HikaShop 2.5.0 in order to see clearly the "move" icon to sort the characteristic while editing a product.
But for the sorting of the values, it is when you edit a characteristic.
Regards,