If you don't want to learn the regex syntax, you can use strfind:
before = '<HTML><FONT color="0000FF">';
after = '</FONT></HTML>';
start = strfind(str, before) + length(before); %or just length(before)+1 if str always starts with before.
end = strfind(str, after) - 1;
result = str(start:end); %assumes there's only ever one match
It's of course a lot more flexible and shorter with regexes:
result = regexp(str, '<HTML><FONT color="[0-9A-F]+">(.*?)</FONT></HTML>', 'tokens', 'once'); %with added bonus it will work with any color, not just 0000FF.
