Wow, I do remember those Donmoor Star Trek shirts. I think I had a gold one. Short sleeve, too (I wanted long sleeve, but it wasn't available). They were pretty well made, considering the production source at the time.
Yeah, I also recall the green one. I definitely didn't want it as I knew it wasn't right, even then.
Here's an image of the green shirt
And a color chart
showing the Donmoor colors compared to the original ones.