When you first start to colorize a stack, resources are copied from the
Color Tools stack into your stack. This process is not entirely completed
until the stack is closed. If you save the stack as standalone application
before quitting the stack, the resources won't make it into the standalone
application -- and color won't work.
Be sure to allocate enough memory to the standalone app to allow it to
display color. Generally, 2MB should suffice. If you're having trouble
with color in standalone apps, be sure to close the stack at least once
before saving it as a standalone application (most people will do this as
part of the normal development process anyway), and then go to the Get Info
dialog box and give the new application at least 2MB of memory.