Always use the MAX line as a reference. If your smoothie is too thick, you can add more liquids or remove ingredients that are thickening agents like yogurts, avocados, and bananas. 1/2 to 1/4 cup of greens should not be the reason why your smoothies are too thick.
You have misunderstood my question. It is the green/muddy brown colour that makes me query if I am using too many greens.
I did nor state that my smoothies are too thick - this is not the problem at all.