When Little Bee and the other three girls are released from Black Hill Immigration Removal Center, they're given clear plastic bags containing their (very few) possessions. Little Bee describes how she feels when she sees sari girl's bag, which is (oh, the irony!) completely empty. Or is it? Well, not exactly, depending on how you see things. Here's Little Bee's take:
"Why do you carry that bag, girl, if there is nothing in it?" I could see her [yellow] sari through it so I decided she was holding a bag full of lemon yellow. That is everything she owned when they let us girls out." (1.42)
This connects with the theme of "Hope" rather nicely, wouldn't you say? For all her talk of life being gray and all that, and preparing to kill herself if bad men come, Little Bee is actually a very hopeful person who tries to find goodness and beauty in whatever she encounters. Her reaction to sari girl's bag suggests that when everything we think is important gets taken from us, we must find something in that nothing, or at least try to, in order to keep on going. It demonstrates that Little Bee's moved on to problem-solving mode – no more suicide plots. She's training her eyes to see any possible opportunity for survival and safety now.
Viewing at the empty bag as a bag of lemon yellow is Little Bee looking for beauty and brightness so she and her readers aren't completely overwhelmed with all the gray. By clinging to the empty bag, sari girl expresses some of the same attitude Little Bee has. We might call it the at-least-I-have-a-plastic-bag attitude. It's an attitude that helps people in dire situations get through them, survive. The bag of lemon yellow also connects nicely with the sun and surf imagery at the end of the novel and is equally ambiguous and complex, a combination of hope and desperation.