BlendMode

type BlendMode =
  "PASS_THROUGH" |
  "NORMAL" |
  "DARKEN" |
  "MULTIPLY" |
  "LINEAR_BURN" | // "Plus darker" in Figma
  "COLOR_BURN" |
  "LIGHTEN" |
  "SCREEN" |
  "LINEAR_DODGE" | // "Plus lighter" in Figma
  "COLOR_DODGE" |
  "OVERLAY" |
  "SOFT_LIGHT" |
  "HARD_LIGHT" |
  "DIFFERENCE" |
  "EXCLUSION" |
  "HUE" |
  "SATURATION" |
  "COLOR" |
  "LUMINOSITY"

Blend mode describes how a color blends with what's underneath it. This property is typically set on a layer, fill or effect (e.g. blend mode of the shadow).

These blend modes are fairly standard and should match what you would find in other image processing tools. [Examples]