If the sugar cane meat is a little red, I suggest you not eat it. If the sugar cane turns red, it means that there is already mold in it. This mold is a fungus called aflatoxin, which has carcinogenic effect, and if eaten, it will also lead to poisoning reaction, which may be life-threatening in serious cases.
Sugarcane is poisonous if its heart is red, and poisonous if its meat surface is a little red, so it can't be eaten. Red sugarcane is toxic, because a kind of Arthrosporus can be isolated from moldy sugarcane, which will produce a toxic chemical with toxic effects, which is manifested as damage to nervous system, liver, kidney and lung.