Johny_D said:
It's much more comfortable to disable controls, due to not changing tabstop and lots of othe options.
Yes, but TextBox control doesn't allow you to control colors when control is disabled, but only when control is in read only mode.
That can be understood, because users have specific expectations when controls are disabled. They expect controls to be dimmed, not flashing in colors. Otherwise, how would the user know which control is disabled if it can't be determined by its specific visual look?