I originally planned this pattern in a single colour, but with autumn approaching I opted for a more colourful sweater. Experiment with alternative colouring ideas - limit the background to one colour and use only 2 contrasting grid colours, or knit each grid line in a different colour.

Main shade (grey or brown):
4 (5, 5, 6, 6, 7) balls
plus
1 (1, 1, 1, 2, 2) balls in each of 4 contrasting colours (green, red, gold, blue).