Showing color options on PDF Invoices

Your Product Addons plugin shows color options on standard WooCommerce emails in a color block which is really nice. However, I’ve tried 3 different PDF Invoices plugins and they only show the color block in black – actually one shows the color as a thin outline but it isn’t inline with the text. Two of the plugins also display the ‘wcpa_label_missing’ meta label on the paragraph field which is correctly removed on emails.
Unfortunately the PDF developers say I need your assistance to fix this issue as they are just outputting content created by WCPA. I don’t understand why it looks great on emails but not on PDFs. Can you help?
Thank you.