Are they both on show? Generally the brighter the finger polish the shorter the nail should be otherwise it looks vampish imo. I tend to go for a clear polish on the fingers if my toes are very bright or a simple french polish otherwise i try and match.
Same colour on fingers and toes can look co-ordinated, but it isn't a 'rule'. I tend to put the colours that make me look awful (coral, atm) on my toes rather than my fingers, but that's my only personal rule.