I never really liked the default selection circle much so I thought it could use a rework.
Import the selection circle three times with each individual under these paths:
ReplaceableTextures\Selection\SelectionCircleSmall.blp
ReplaceableTextures\Selection\SelectionCircleMed.blp
ReplaceableTextures\Selection\SelectionCircleLarge.blp
Keywords:
simple, smooth, circle, selection, selected, UI