If there is a diamond target on the switch stand it is green. The round targets are yellow or red.
Imagine that you are standing at the mainline-ladder switch looking at a facing point switch stand. If you see green, the switch is lined for the main but if you see red the switch is lined for the ladder-or down the lead. Now look at the next switch we’ll call it #1. If it is green the switch is lined for the lead if it is yellow it is for #1. The thing to notice here is that the main line was Green-Red and the inside switches are Green-Yellow. In the case where there is not a color, as in the case where the diamond target is not mounted on the switch stand, you are lined for the main. If you see color, red or yellow you are going to turn out.
As always there are exceptions etc. And I welcome further comment or correction
Thanks
Woody