The problems with your fiddle were as follows:
1) You hadn't included the jQuery library.
2) You hadn't closed the each loop correctly (missing parenthesis).
3) You were missing the id selector # from "myButton".
Here's an updated, working fiddle.
Note, however, that you could simply do this:
$("#blue, #red, #green, #black, #purple, #orange").hide();
Or better, put all of those in a containing parent element, and simply hide that, or use $("#parent div").hide();.
You can store the result of that selection in a single variable, rather than the 6 you currently have, as jQuery methods tend to operate on each element in the matched set without the need for a loop.