I have light brown hair, past my shoulders. How would red streaks look?

It would depend whether your light brown hair is with red highlights or is in fact more of an ash tone. If the answer is yes to red highlights then the red streaks would be complimentary. If your light brown hair is more ash in color then I would suggest considering going to ash blonde streaks.

I have light brown hair, past my shoulders. How would red streaks look?

i wouldn't go flame red but i think they will look nice

a good sylist/colorist will be able to recommend a nice tone for you. or pick from the selection at the store - something that stands out but doesn't over power

I have light brown hair, past my shoulders. How would red streaks look?

It would look weird.

I have light brown hair, past my shoulders. How would red streaks look?

mousy brown and red looks manky lol.. creamy blonde highlights or chocolate brown lowlights would probably suit u so much more.