Added color and font styles.

Sources/SwiftMathRender/MathRender/MTColor.swift

@@ -0,0 +1,25 @@
+//
+//  MTColor.swift
+//  MathRenderSwift
+//
+//  Created by Mike Griebling on 2022-12-31.
+//
+
+import Foundation
+
+extension MTColor {
+    
+    static func color(fromHexString hexString:String) -> MTColor? {
+        if hexString.isEmpty { return nil }
+        if !hexString.hasPrefix("#") { return nil }
+        
+        var rgbValue = UInt64(0)
+        let scanner = Scanner(string: hexString)
+        scanner.charactersToBeSkipped = CharacterSet(charactersIn: "#")
+        scanner.scanHexInt64(&rgbValue)
+        return MTColor(red: CGFloat((rgbValue & 0xFF0000))/255.0,
+                       green: CGFloat((rgbValue & 0xFF00))/255.0,
+                       blue: CGFloat((rgbValue & 0xFF))/255.0, alpha: 1.0)
+    }
+    
+}