On the 2600 you had a switch that was for toggling between black and white and color. I never really understood what this was for. If you were playing on a B&W TV it would automatically show up B&W regardless on what you had the VCS set at, and why would one want to play in B&W if you were on a color set? I know on later releases it was used as basically another select switch and gave your game yet another option of difficulty, and some "newer" games have no reaction when the switch is flipped. What was Atari's reasoning for the B&W and Color toggle switch then?

Maybe it was kind of a "fine tuning" device sorta thing? Dunno, good question.

It had something to do with the depth of color on some blacks and greys. Basically it "optimized" the graphics for B&W. It's been many years since I actually played a regular color game on a B&w TV, but I put the two side by side once and noticed a difference in tone for certain colors.

My honest opinion is that Atari didn't want to potentially scare off customers who would end up playing their systems on a b&w TV so they put that switch on it in order to show shopping moms that "HEY YOU! YEAH YOU! SEE THIS COLOR/B&W SWITCH? THIS MEANS YOU CAN STICK THIS CONSOLE IN THE BASEMENT REC ROOM AND LITTLE JOHNNY CAN BE OUT OF YOUR HAIR PLAYING THIS ON THE ANCIENT BLACK AND WHITE SET YOU HAVE DOWN THERE INSTEAD OF ON YOUR BIG, NEW ZENITH THAT YOUR HUSBAND WATCHES CHARLIE'S ANGELS ON INSTEAD OF PAYING ATTENTION TO YOU."

You could very well be right. Its odd that they kept that option on the system up until 89 on the 2600 Jr. when b&w, while not obsolete, were definitely in the minority though.

I know some games used this button to add extra features to their games, like a pause feature in Fantastic Voyage.

I had a B&W TV in my bedroom in the early/mid 80's with a 2600 hooked up to it. When I toggled the switch from color to B&W, you can clearly see a difference. If I remember right, it looked better when on B&W.