To all people with a purple shop:
The purple coloration indicates
the time on the device is out of sync with the time on the
game's servers. To ensure your device's time is correct, please check that the time, date and year are very correct on your device.
If they are not, fix this.
Then, try turning off "Set time automatically"on your device (Settings>General>Date& Time). Then turn your device*off, and synchronize it with iTunes on your computer. Once that is complete,
ensure "Set time automatically" is set to "on" again *and re-launch the game.
Please note that the amount of time it will take to return to normal is based on but not equal to the amount of time your device has been set incorrectly by.
Hope this helps anyone having the problem