None of them really. At least from what I have noticed with a character that was doing different levels of recipes recently.

You might get a higher chance for the two Purple ingredients at a higher level of Recipe. My mid level guy was not getting as many, but still getting some purples. Note, this is Recipe Level, not the one that lets you make Blue or Purple or Gold recipes. Main reason is you can make Purple recipes down to L20 or so, so there has to be a way for someone who can make only those to get the purple ingredients. Although you have to be pretty leveled in Provisioning to unlock Purple recipes so most people are going to have a higher level of recipe at that time.

Now, the Recipe you get from the Crafting Writ reward is tied to your Recipe Level, good if your chasing the lower level Blue and Purple recipes as it is a decent way to find those (90% of the less than L50 Blues and Purples I have got from Writ Containers.