This may not be the case. Theoretically, it should become a red Supergiant star first, but at the end of its life, the superstar may erupt a lot of substances around it, making it lose its low-temperature outer layer and expose its high-temperature inner layer, so it may become a blue giant in the Red Supergiant star stage.

The actual example is 1987, the supernova SN 1987A in Magellanic Cloud. After the discovery, it was found that there was a blue giant in the explosion site itself, not a red giant as we usually think, so the above conclusion was reached.