There are three parts to this:
1. Is it something that reasonably shouldn't harm your unintended victims?
2. Does it satisfy the catch of your intended victim?
3. Does it fit cleanly into one of your evocation elements?
A Dawn attack likely satisfies 1 and 2 but will often fail on 3 if you don't have SM: Summer Court or something equivalent.
That said, there are a few examples in the book, Ghost Dust and Sunburst pg 304. If you can fit their effects into your evocation elements, then go ahead, otherwise you are stuck doing Thaum (either directly or with potions).