Actually when someone were to said he is a true blood or true blue " this or that" It is usually a statement of total faith or dedication to something. A believe that is deeper then nationality of origins, race...etc. For example, someone who, against his own usual self serving interest for his own cause or another is now willingly to give up his own belief, time, worth and even his life for the common cause... IS a true blue or blood of that cause or country. There is no local or foreign in that equation.
To me that is where I draw the lines. I don't care where you are from. The idea is you are here, you know what is expected of you here, you do good and follow the law of the land, you learn to assimilate to the cultures here and give up your bad old ways and make an effort to contribute to the joint success and survival of the land or company or whatever.. That is what being a true blue is about.
Other then that.. really? Why should I call it that? If something happens and you are the first to run? That is not one I would call a True Blue. You got to be there for not only the good times, you got to be there for the bad as well. Hard ting to do even for some Singaporeans I see or worst, turning traitor. Even in peace time we can see that. Instead of stepping up to help the nation, you profit from it in the name of politics or corporation.