Emulsion paint matt white - small quantity (Sharmans Cross B91)

I need to paint approx 0.25 sq meters (< 3 sq feet) of ceiling with emulsion paint matt white. Before I buy several litres, does anyone have a small amount unwanted? Probably only requires 200-300 ml, allowing for 2 coats. Doesn't matter if it's white or brilliant white but please not a shade of white.