Talk with her.

You and some of your men acting as bodyguards approach the aging woman, and you step up first. "Excuse me, Miss... Why are you out here all alone?"

"The White Serpent, the son of the white emperor, will killed by the Red Emperor." She'd say, repeating herself as she walked by.

You stood there, blinking a few times. You considered what she said as your bodyguard looked at each other with confusion.

Fuck it, you've come this far by bullshitting let's give it another go. "I think she means that the Serpent represented the Sendaki, and I represent a new dynasty."

"What on earth gave you that impression?" One of you bodyguards asked. To which you said "Well, is it any coincidence that we took out a snake on our way here, and suddenly this woman mentions that even though she wouldn't have seen it? That and Red is a very adventuring and exciting color, which when we consider our situation, that is our color. The White is clearly the Sendaki colors as well."

The same bodyguard reacted as though he hit with a shock of electricity, taken aback by the words you listed off. "The Sendaki's colors are black!"

"White, black, they're all colors." You replied. "Come on, let's set up camp nearby and rest our feet."