This blog has an image from Zhangye, Province of Gansu, China.
This mountain is made of earths or stones in gradients of often bright colors, predominantly red but also yellows and blues.
However I cannot find directions anywhere to the landform, from Zhangye or anywhere else.
I suspect it's in the mountains SW of Zhangye, but I'd need either a satellite image or clear definitive instructions to be able to accept an answer. Just "go to Zhangye" would not be enough :(