iOS Swift UIImage subscript extension to get pixel color

UIImage+PixelColor.swift

import UIKit

extension UIImage {
    subscript (x: Int, y: Int) -> UIColor? {
        guard x >= 0 && x < Int(size.width) && y >= 0 && y < Int(size.height),
            let cgImage = cgImage,
            let provider = cgImage.dataProvider,
            let providerData = provider.data,
            let data = CFDataGetBytePtr(providerData) else {
            return nil
        }

        let numberOfComponents = 4
        let pixelData = ((Int(size.width) * y) + x) * numberOfComponents

        let r = CGFloat(data[pixelData]) / 255.0
        let g = CGFloat(data[pixelData + 1]) / 255.0
        let b = CGFloat(data[pixelData + 2]) / 255.0
        let a = CGFloat(data[pixelData + 3]) / 255.0

        return UIColor(red: r, green: g, blue: b, alpha: a)
    }
}

I want to extract RGB values for all pixels from a frame captured during ARSession. The CVPixelBufferFormat for that is of type kCVPixelFormatType_420YpCbCr8BiPlanarFullRange. Will this code work for this format type as well?
I am new to Swift, I am having a tough time trying to understand the format types and difference in manipulating them.

Doesn't work on black for some reason