The fields around Luthrie and Moonzie are agate-finding locations for intensively red colored agates. Besides these highly desired colours other agate-nodules are showing pastels or bluish-grey colours in combination with white.
More informations about scottish agates are given in Dr.H.G. Macpherson´s book “agates” (published by the British Museum (Natural History) and the National Museums of Scotland).
You can find more informations about scottish agates on the following webpages:
Chris Harlows webpage about scottish agates
Nick Crawfords webpage scotsagate
H.Currie Minerals of Scotland