I'm fishing Table Rock this spring, been doing research on craws. What causes craws to change color, and is there anyway to adequately predict from 12 hours away haha? 

I figure that they start brown/blue and turn to the generic red craw color as the water reaches it's peak temperature?

There are hundreds of different crayfish species and colors. Each specie has about 4 phases of coloration during the year and adapt the whatever coloration they are living in.

You can look up crayfish species by state or set traps and study the varieties where you fish.

Crayfish out grow thier shells and molt, the old shell sheds leaving a soft under shell called a soft shell, bass prefer to eat soft shells and the coloration is usually very muted compared to the hard shell.

Tom

If you are going to be there for a few days you could drop a small crayfish trap down. I have done this on my local lakes and discovered that we have several different species with a wild variety of colors.

For largemouth I have always felt profile and size trumps color selection (and for color I usually stick with something dark and bland). River smallmouth seem to be more particular about color in my experience but I still feel that does not trump profile.

Here's some links to the species that I see most often on Table Rock. The Northern Crayfish and Spothanded are the most common ones it seems.

http://mdc.mo.gov/discover-nature/field-guide/longpincered-crayfish-long-pincered-crayfish

http://mdc.mo.gov/discover-nature/field-guide/northern-crayfish-virile-crayfish

http://mdc.mo.gov/discover-nature/field-guide/golden-crayfish

http://mdc.mo.gov/discover-nature/field-guide/spothanded-crayfish

Most springs, a translucent olive/brown wiggle wart is the ticket.   Some of them have a little tinge of orange on the lip.  The few times that I fished Table Rock as a co-angler, that was the co-angler ticket.   I haven't fished BFL's lately, but I do have a box of appropriate colored wiggle warts, for the next time I do visit Table Rock in the spring.

Edit - just went to the Storm Website and looked.   Phantom Brown & Phantom Green Crawfish were the closest colors, as I recall.  Those colors on the web site didn't look like the same colors as I bought early 2000's at BPS.   I'll have to go out to my fishing shed and look some time.   At the time, I remember being beaten by a bait that I wasn't familiar with at the time, so on the drive home I stopped at BPS and bought several of each color I saw different guys using.   I'm pretty sure there are a couple dozen baits in a box labeled "Springtime Wiggle Warts"

The guys who won with that bait were throwing them on a 7' or so medium rod with 10 lb line (bait caster)

One guy was throwing a 7.5' Med spinning rod - 10 lb braid and a short fluorocarbon leader.   He was doing an incredible job of covering water.  Sometimes, fishing out of the back of the boat that is the game.

Crayfish also change color depending on the food they eat,type of algea and so on..

My cousin and I were prefishing Table Rock for the organization  championship we were a part of . We were fishing Salt craws about 20 foot deep .His lure seemed a little heavy so he retrieved it super slow . there was a  brown crawdad with bright orange pincer tips holding onto his lure  . We switched to brown and orange jigs and pork and caught two keepers . It was the only thing we had going so thats what we did during the tourney . The weather cahnged and we got skunked . I did lose two keepers pitching to standing timber and letting the lure to sink twenty foot down .