I to have experience this. I planted moon seeds with morning glory seeds and nothing happened. I thought too cold too wet something. then one day I noticed a plant. I assumed it would be a morning glory. the flowers come out in the morning and are a light very light blue, they have the moon flower star of darker blue, late late evening they turn pink and the next day they last a few hours then they drop. What Im wondering is how do you get seeds from these types of plant. I would love to do this again planted with the moon and morning glory

What color is your clematis??
The moonflower probably didn't cross with the clematis(an entirely different species), but it is very likely that a bee, or other such pollinator, brought some pollen from another mg nearby, and they crossed, to give you a colored moonflower.
There is also a chance that your moonflower just put out a mutation.
What color are they turning out to be? Do you have any pictures?
I'd love to see it! Save the seeds from this one! I'd love to trade!
-T