My hair color is originally dirty blonde. My highlights were wearing off so I redid it tonight and I accidentally left it in too long and my hair is now super blonde with like a orangish tent to it. What will happen if I try putting in a light brown tomorrow morning? What will be the outcomes?

For sure re-die it a dark brown. The reason for dark brown is because it will take out the orange and the dark brown will lighten because of the blonde. Then when the colour lightens you will have a nice light brown. If you colour with a light/medium brown, it will lighten after a week back to a yellowish/orange colour. Good luck! I have done this before and that's what I did. If you don't want to die it right away you can use blue shampoo as well, to get rid of the orange colour until you die it next. :)