Rocket Board is a super awesome portfolio Wordpress Theme with METRO style. You can set each thumbnail size as 1x1, 1x2, 2x1 or 2x2 easily. This theme also allow user to set specific colour on each metro box or just use the default colour from admin panel. You can also set the first state of metro box to show as colour box or show as feature image. This theme has 9 predefined background colours and 8 overlay patterns...or if you need to upload your own background image, it's just fine