How are the colors faded in that way?
I'm guessing you're talking about the vertical gradient, which, can be derived from a program like handplane. Then, you can color it in a photo editing software such as GIMP through color multiplication.
How was the glass made
If you are using software like Unreal, Cycles, Blender, etc, you can use a Fresnel function with a sharp falloff and a blue gradient. This will round the corners however, and if you want to perfectly duplicate the bottle, you will have to have two models: one for the inside and one for the outside of the bottle, colored accordingly(You can easily do this with a thickness modifier, then separate the parts manually). Then, draw the inside over the outside with this method.
I'm in the process of learning more Blender
As am I. Welcome to the community!