Your photos don't show at all. Maybe you haven't had enough posts on this site.
But, does not make too much difference, as you describe a rainbow colored area, which is a typical "look" for a cracked screen, or maybe just a pressure crack, which might not be too visible unless power is on.
The fix is the same, you can't repair a crack, you just replace the screen.
I see your last picture, with the area in the center of your screen.
- - It's a broken screen. The various colors happen, because the light through the various layers in the cracked area reflect back at different angles, resulting in a rainbow effect. Sometimes shows as a plaid or checked pattern, and sometimes like yours as colors radiating away from the break.
Finally, as there are multiple layers of extremely thin glass, you can have cracks in the internal layers, but no visible external damage. And, the damage might only appear when power (and the backlight) is turned on.
Again, there's no more that you can do, except replace your LCD screen. It's broken