Need help with reflective paint

I need help with the paint that is ideal for a small grow box.

So far i only have aluminum but the problem is that it retains alot of heat making the temperature inside my box unfit for my ladies.

My question is, is there a spray paint that is ideal for reflective purposes? If so, what color and if possible where and what brand may i buy this paint in.

Thank you.

white's the best color for reflectivity, you can also get emergency blankets they are mylar and reflect a lot more light then white paint.

where can i find these emergency blankets?