Sorry to hear that but I tried all three Morpheus in my Pentax, sold all three they gave a yellow tint to the view. I really wanted to like the 12.5 mm but comparing it to the APM hands down the APM is a much better eyepiece in all respects from its quality of build to its true to color clear view.
I am very happy with Morpheus 12,5 and 17,5mm to my Pentax 65mm scope. Never noticed a yellow tint but maybe I am less sensitive to that.