If its what you love, then thats what it should be painted. I think it will look very nice.

There are no rules. If you love it, paint it. It's paint, not a gaping hole in the ceiling: )

If you don't love it up there? You paint over it. A clean white or tinted white would hardly end the world.

I think they look baby blue to me even full strength so use it full and if you love it thats all that matters . I do love blue ceilings in porches and without seeing your house I have no clue as to what the blue doors will look like,

It’s going to look different on the porch ceiling. Did you test your 50% sample on your ceiling? It’s also going to look different at different times of day, and different times of the year because of the position of the sun and reflection off landscaping. It might be more intense in places where soffit and ceiling reflect against each other. It may turn out that your ceiling looks darker than your door if you use the same color.

Once you examine it on the ceiling and in a corner of the ceiling through different times of day, if it is too intense, you can choose a more muted or complimentary shade. It doesn’t have to be simply a whiter shade, maybe a lighter more subtle shade that has some gray in it, in addition to the white. It may produce the feeling of a blue sky on the ceiling with less pigment because of the increased intensity of the shade combined with corner soffits reflecting against the ceiling.

I chose a lighter shade of solid stain for my ceiling than the siding, because I didn’t want the porch to feel like a cave. Both shades are medium, though, not light toned because I did not want to use paint on the rough wood.

Thanks for the responses.

I realize that whatever I do is certainly not going to cause the end of world or represent an expensive, forever, set in stone decision. It's just that with the scope of this entire project (it's big!) I've got decision fatigue. I mean, decision making is not my super power to begin with.

And honestly, there are so many things that I feel I can't be 100% sure of until they're actually done. So I'm trying very hard to get this right the first time. I think there are a few more steps I can take to make that happen...

I’d be tempted to do the ceiling in Mountain Air which is one of the coordinating colors and will be a little more low key to let the door shine

@la_la Girl - those are the exact words our builder's wife (designer) used: "let the door shine."

I just went outside and slapped some Billowy Breeze on my old white front door, and some Billowy Breeze 50% on the small ceiling above it.

That's a starting point for me to really see how it looks.

Thanks again to all who responded.