I like the 1st all blue one.

To spray baste the layers together, either find enough floor space or if you can put together a couple of tall tables what works great. How big is it? What I do is after completing the top, I make the back a few inches larger on all sides and then cut the batting around the same size as the backing. either on floor or table, tape your backing piece (make sure you press it and your top first) so that is flat and a little tight, but do not stretch it. I start by taping the center (on a seam if the back was seamed) on one end then I move to the other end and tape it across from the one I just taped. Then move to one side, smooth it out and tape again, I do mine about 12-18 in apart using blue painting tape, smooth to corner, tape corner. Do the other end keeping it smooth and tight, but not stretched. I then lay my batting over the backing, smooth it out so there are no wrinkles, but do not stretch, fold the batting in half and spray the first half of the back, or on the batting, whichever you prefer, lay it down and smooth it out, lifting up if you need to. The basting spray is temporary so you can move and restick it. Then fold the other half of the back up spray it then smooth it down. I then lay the top on the batting smoothing it out, then fold half up again, spray & smooth then fold the other side, spray and smooth. I don't pin baste any more, it is too hard for me. There are several different spray basting cans out there, my personal favorite is the 505. You will probably want to spread some news papers or as I do, old painting sheets around after you tape to protect the surrounding surfaces of over spray.
I hope this helps. I'm sure there are some tutorials on basing around here somewhere. Good luck. I hope it goes together smoothly for you.

They're all good, but I like the first one best. HOWEVER, I see lots of pictures of quilts that other folks love and I hate ... either pattern or color choices or both. Untimately this is a decision only you can make.

First of all, I think all of them are very nice. I would personally like to see #3 variation with the other blue from #1 in the "empty" squares. Any way you do it will be gorgeous!

I vote for #1. I'm sure any of the three would be beautiful, but I prefer #1.

I like number 3.

I like the first one with different shades of blue.

Number 1 is brilliant. I love it!!

For what it's worth, I like the deep blue combo the best. However, I would try switching the royal blue you used in the squares with the dark blue of the triangles. I think that would cause the star effect you have going on in the mauve mock up to be seen. If you don't want it to be too busy as you said remember KISS - Keep it simple silly! stick to one color choice and rely on color value.

It is a really pretty pattern.

I love the green/teal colored one. It really pops!