I see various crank bait series offered in both  the black back chartreuse color and then the chartreuse / green / blue back (i.e. citrus / parrot) color . 

Is there a rule of thumb (sky / water color) when you might choose the basic black back chartreuse crank bait color versus the chartreuse / green blue back color crank bait ? Thanks in advance - the reasoning to choose between these two crank bait color patterns has always been a bit of a mystery to me !

Black and yellow is good for muddy/stained water and the colors contrast significantly as the bait rolls on retrieve. Think of the bait as flashing between black and yellow. Like a strobe light for muddy water.

Parrot color is just a sunfish perch imitators for stained to tannic water. Good for medium/deep cranking. Too flashy of a color in my opinion for shallow clear water.

Color catches fishermen.

But, to keep it simple I see it like this.  Loud colors for murky water.  Natural colors for clear water. 

Black and yellow is good for muddy/stained water and the colors contrast significantly as the bait rolls on retrieve. Think of the bait as flashing between black and yellow. Like a strobe light for muddy water.

Parrot color is just a sunfish perch imitators for stained to tannic water. Good for medium/deep cranking. Too flashy of a color in my opinion for shallow clear water.

Well I don't fish too deep but a combo of stained water and overcast skies could be good for the black back / chartreuse color .