Im still trying to figure that out. i used to fish white...but now im thinking black or darker colors might stand out more. regardless of color, anything that produces vibration or rattle will help the fish key in on it easier when the visibility is limited due to murky water.
Its 4am, and im sitting here at work...reading a "Field and Stream"...what do you know though, it has an answer to your question---
"in tannic or murky water, stock up with gold flash, yellows, oranges, browns, and black. Clear water calls for silver flash and naturally imitative colors like white, dun, tan, olive, and grey. Chartreuse and moss green is good in any water. and a splash of red never hurt..."