Nice colour splash, Ving! It looks like you haven't unmasked the tyres (they are BW?). Try it with colour on the tyres... they're part of the tractor too ya know!
Al.
PS. The red one, for all the usual reasons, but I'm impressed with how authenti the colour looks in the desaturated one, until I look at the grey part of the engine... something looks unrealistic about that in the desaturated image compared to the red one.