(light brown, not blonde on curlies)
I think maybe a mix of Ash Blonde and Light Chestnut. You might have to play with amounts on strand tests, depending on how it comes out with just the Blonde.
If you want to save on shipping, you could get 2 Light Ash Blonde and 1 Light Chestnut. Then you have some to mix in if needed. Or wait to see how it comes out with the Blonde.
One box should be enough if your hair is not long or thick.