CalDavSynchronizer.Conversions.Msft.HtmlCssParser.ParseCssColor C# (CSharp) Метод

        private static string ParseCssColor(string styleValue, ref int nextIndex)
        {
            //  Implement color parsing
            // rgb(100%,53.5%,10%)
            // rgb(255,91,26)
            // #FF5B1A
            // black | silver | gray | ... | aqua
            // transparent - for background-color
            ParseWhiteSpace(styleValue, ref nextIndex);

            string color = null;

            if (nextIndex < styleValue.Length)
            {
                int startIndex = nextIndex;
                char character = styleValue[nextIndex];

                if (character == '#')
                {
                    nextIndex++;
                    while (nextIndex < styleValue.Length)
                    {
                        character = Char.ToUpper(styleValue[nextIndex]);
                        if (!('0' <= character && character <= '9' || 'A' <= character && character <= 'F'))
                        {
                            break;
                        }
                        nextIndex++;
                    }
                    if (nextIndex > startIndex + 1)
                    {
                        color = styleValue.Substring(startIndex, nextIndex - startIndex);
                    }
                }
                else if (styleValue.Substring(nextIndex, 3).ToLower() == "rbg")
                {
                    //  Implement real rgb() color parsing
                    while (nextIndex < styleValue.Length && styleValue[nextIndex] != ')')
                    {
                        nextIndex++;
                    }
                    if (nextIndex < styleValue.Length)
                    {
                        nextIndex++; // to skip ')'
                    }
                    color = "gray"; // return bogus color
                }
                else if (Char.IsLetter(character))
                {
                    color = ParseWordEnumeration(_colors, styleValue, ref nextIndex);
                    if (color == null)
                    {
                        color = ParseWordEnumeration(_systemColors, styleValue, ref nextIndex);
                        if (color != null)
                        {
                            //  Implement smarter system color converions into real colors
                            color = "black";
                        }
                    }
                }
            }

            return color;
        }