Hello. How do I recreate this image w/ gradually fading blue overlay

Hi,

I'm a newbie to photoshop and I'm having difficulty recreating the image below. I know how to change the opacity of an enitre image with a new layer using blending options but I wanted to recreate the effect in this image, specifically the blue overlay I think that's what it's called) that starts off a solid colour on the left side and gradually lightens left to right.

I'm also trying to use the exact blue color, is there a way to sort of take it from the image rather than trying to recreate it myself?

Thank you