Color can potentially by defined in other than RGB colorspace

[xhruso00]

Describe the bug
hexString for NSColor extension provides invalid values for CMYK colors or other non RGB colors selected using NSColorPicker.

To Reproduce
Steps to reproduce the behavior:
let color = NSColor(deviceCyan: 0, magenta: 1, yellow: 1, black: 0.1, alpha: 1)
print(color.hexString) returns #000000

Expected behavior
print(color.hexString) should return #B50E20

Screenshots

Desktop (please complete the following information):

• all versions

Additional context
FIX: convert color to RGB colorspace first. Use generic color space

extension NSColor {
    /// SwifterSwift: Hexadecimal value string (read-only).
    var hexString: String {
        var rgbColor : NSColor = self
        if colorSpace.colorSpaceModel != .rgb {
            rgbColor = usingColorSpace(.genericRGB) ?? NSColor.black
        }
        
        let components: [Int] = {
            let comps = rgbColor.cgColor.components!.map { Int($0 * 255.0) }
            guard comps.count != 4 else { return comps }
            return [comps[0], comps[0], comps[0], comps[1]]
        }()
        return String(format: "#%02X%02X%02X", components[0], components[1], components[2])
    }
}

• I've read, understood, and done my best to follow the Contributing guidelines before opening this issue.

[guykogus]

@xhruso00 thanks for catching this. Why don’t you try and submit a PR to fix it?