check the blending Mode of path item (stroke or fill color)

To check the blending Mode of a path item I use this:

if (app.activeDocument.pathItems[0].blendingMode != BlendModes.NORMAL ) {
    alert("Not Normal") }

How can I test, if the stroke and/or the fill Color of the path item having another blending Mode than normal (the path item itself is in blending Mode normal)?

Here a simple example for this:

Has anyone a useful idea?

(And sorry for my terrible english)