$re = '/(?:(?<!\\\\){((?:(?:red|blue|black)\.?)+)(?<!\.)\s((?:(?:[^{](?!{|})|\\\\{|\\\\})+.)?))|((?<!\\\\)})/';
$str = ' {red.blue.black {red \\{{texxt\\{text} text}213
{red.blue.black. \\{text \\{text}text{text} text
{red.blue.black text \\{texttext{text\\} text
{red.blue.black text \\{texxt\\}text} text
{red.blue.black text \\{text{ text{text} text
{red.blue.ggg text \\{text}text{text} text
{red.blue.ggg text \\{text}text{text} text
\\{red.blue.ggg text \\{text}text{text} text
{red text \\{text}text{text} text
{red {red das}text \\{text\\}text{text} text
\\{red text \\{text}text{text} text
\\{red.blue.black text \\{text}text{text} text
{red.blue.ggg text \\{text}text{text} text
{red.blue.ggg text \\{text}text{text} text
\\{red.blue.ggg text \\{text}text{text} text
{red text \\{text}text{text} text
{red text \\{text}text{text} text
\\{red text \\{text}text{text} text
{red.blue.black text \\{text}text{text} text
{red.blue.black text \\{text\\}text{text} text
\\{red.blue.black text \\{text}text{text} text';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php