Color is unimportant...Just ask Obama.
Triumph uses a proprietary Mobil, blue colored antifreeze..
Page 12.4 of the OEM Shop manual states:
Coolant:
An all-seasons type of anti-freeze is installed in the cooling system when the motorcycle leaves the factory. It is coloured blue..... (I love the English verbage)..., contains a 50% solution of ethylene glycol and has a freezing point of -35 degrees centigrade or -31 degrees farenheit.
Any ethylene glycol or propolyene glycol (if you prefer the enviromentally friendly stuff) will work just fine, green, blue or red, it's just dye. All antifreeze sold over the counter today has corrosion inhibitors and is perfectly safe for aluminum and alloy engines.
Extended life is a no-no. Extended life is a synthetic formula and will turn to a gooey sludge if mixed with ethylene/propolyene glycol.
Even though the factory don't suggest it, because the engine is wet linered, I'd suggest adding potassium permagnate in solution with deionized water in the antifreeze. You can readily purchase it as Cummins Engine Specification DCA 4 precharge. A single bottle should provide more than adequate protection.