In the TextDrawingArea class you should have 2 methods, assuming you have the standard obfuscated client. method389 and method390
In both methods you should see something similar to

for (int index = 0; index < s.length(); index++) {
            if (s.charAt(index) == '@' && index + 4 < s.length() && s.charAt(index + 4) == '@') {
                int j1 = getColorByName(s.substring(index + 1, index + 4));
                if (j1 != -1) {
                    j = j1;
                }
                index += 4;
            }
}

Above that you're going to want to put in this code
            if (s.charAt(index) == '#' && s.length() >= index + 1) {
                String newString = s.substring(index + 1);
                int hashIndex = newString.indexOf("#");
                if (hashIndex >= 0) {
                    String color = newString.substring(0, hashIndex);
                    String formattedColor = color.toLowerCase().startsWith("0x") ? color : "0x" + color;
                    try {
                        int colorHex = Integer.decode(formattedColor);
                        j = colorHex;
                        index += color.length() + 1;
                    } catch (Exception e) {

                    }
                }
            }