I have a Huawei P20 Lite and I've had it for over half a year now, a month after I got it it dropped out my pocket and smashed quite badly, It was annoying but I got used to it and had no problems, a couple months later a very, very faint dimming began to happen around most of the cracks but its barely even noticeable so I assumed there was just a little bit of pressure round the cracks, no big deal. But today I noticed a purple mark about a cm long in between my G key and my V key on the keyboard, I thought nothing of it and moved on, a couple hours later I was watching a video and I saw the mark again but it was even longer, about 2cm, I came out of the video to see if it was still there and it vanished, after experimenting a little more I found it only shows on black/dark objects, but its gone on white, it's really weird, if anyone knows how to help plz do, I'm happy to answer questions.