Are these the same clematis?

This is Blue Bird. Bought it last year.

This is an unknown from a friend. Planted a very small little self seeder a couple of years ago

Blue Bird has more petals than the other, but the color is identical.

If the petals are different I dont think it is the same - you would not believe how many clematis there are of that almost identical color!

Jo you might try posting those on the clematis forum.

No, they're not the same. The second has what looks like a pretty typical Clematis alpina-type flower.
Also, if the second was self-sown (I think that's what you are saying?), it would probably not be possible to assign any cultivar name to it. (Well, it wouldn't be correct to do so, at any rate). For example, our yard is full of C. alpina seedlings, probably the offspring of C. alpina 'Pamela Jackman' (an assumption, since it flowered and seeded so heavily)... if I collected seeds from the old plant itself, they'd be corrected called C. alpina ex.'Pamela Jackman'; "ex." indicating "from" that variety, though they will not necessarily turn out to look like it! (In fact, the resulting offspring have an incredible range of colour and flower form - white, pink, blue, purple, single, double, etc.. You'd have to take cuttings to actually reproduce the cultivar.)

I too have a yard full of clematis seedlings this year - some am letting grow and giving away!
They are most likely from C.Helsingborg or C. Francis Rivas - interesting to see what color they will be !

I was given a seedling of C. Constance last year - it is still pretty small at the moment but does have a couple of flowers. But instead of the rich pink/red of Constance they are very pale. So if I understand you correctly Lori the color would be anything including perhaps the original? If the color is not going to come true I will just have to go out and buy one!

Yes, and yes.