VBA Visio - Delete "red" Shapes

Hello,

i want to delete all "red" (see the Picture) shapes, but i cant

find the property in vba, which Shows the Color of a shape.

Thank you for your help.

(At the Moment iam not allowed to upload Pictures, so what i mean with red is the Color of the "lines". Normally all "lines" are black, but there can be red.)