Heard about this idea while listening to a podcast. It's fairly simple it takes a photo(s) you pick and adds the average color of the picture as a canvas to the long side of a photo. For tall photos it will add it to the side, for short it adds it above. Useful for posting photos online via Instagram and other sources.

I have not added in the code to post it anywhere this will simply give you a preview screen/share sheet (at this time).

You will have to have Toolbox Pro to use this shortcut. At this time it won't come up as a selectable option under the required apps area so I am putting it here and will change it later once I can.