C++ (Qt)
class SQLSyntaxHighlighter : public QSyntaxHighlighter
{
public:
    SQLSyntaxHighlighter (QTextEdit *te) : QSyntaxHighlighter (te) {}
 
    virtual void highlightBlock (const QString& text)
    {
	int pos = 0;
 
	static QRegExp rgx ("^\\s*(--)");
 
	if ((pos = rgx.search (text, pos)) != -1)
	{
		setFormat (pos, text.length(), Qt::green);
		return;
	}
 
	setFormat (0, text.length(), Qt::black);
 
	static QRegExp rw_rgx ("\\b(?:select|from|where|and|case|when|then|else|distinct|all|null|"
			"is|like|between|not|count|group|by|having|order|inner|outer|right|left|"
			"join|on|using|union|exists|in|as|intersect|except|coalesce|insert|delete|into|update)\\b", false);
 
	pos = 0;
	while ((pos = rw_rgx.search (text, pos)) != -1)
	{
		setFormat (pos, rw_rgx.matchedLength(), Qt::blue);
		pos += rw_rgx.matchedLength();
	}
 
	static QRegExp o_rgx (":(\\w*)");
 
	pos = 0;
	while ((pos = o_rgx.search (text, pos)) != -1)
	{
		setFormat (pos, o_rgx.matchedLength(), Qt::red);
		pos += o_rgx.matchedLength();
	}
    }
};