need help dating this tricel dress with stunning blue print

[Ineke Veenstra]

Stunning dress with blue print.
I read that tricel is introduced in 1957. But how old is this dress? is it late 50's, 60's or maybe 70's?

 

[Circa Vintage Clothing]

Great print! I'd put that into the '60s but the label is looking towards the more modern end - is the skirt length original? If it was shortened from a long length, it could go into the late '60s, but otherwise I'd go early to mid.