Seahawk

4 minutes ago, Damien Symonds said:

It's fabulous.  All that remains is a very slight gradient mask from the bottom up.

Awesome, thank you so much!

First shot is without rainbow. Second is with rainbow added. 

I used the PS default rainbow gradient and made it radial. I then changed blend mode to screen. Then lowered the opacity to 50%. Then made a layer mask and drug a linear black to white gradient from bottom of rainbow to top since rainbows disappear as they get closer to the ground. I'm wondering if this looks realistic and whether or not you'd know it's fake just by looking. 

Took the blur layer off. It just now has the brightness/contrast layer.

I retried my attempt this morning and this is what I came up with.

Hey all,

So I have already tried Damien's way replacement technique and I am not getting the results desired. The tree is giving me tons of issues so I'm wondering if someone else knows how to make this sky swap work.

Here are the two images. I am trying to put the blue sky with clouds behind the tree.