Checking Water Level

[Pierce]

My expansion tank is discoloured and it is difficult to see the water level and the graduations.Recently while checking using a small torch (lens about an inch across) after removing the cap I shone the torch down into the tank and the level and graduations were easy to see.

[Ardent]

Every day is a school  day.

The coolant level can be a bit erratic, but this is the first post where the bottle itself is in question.
Cannot say ever had an issue of seeing what the level is.

Stock tank?
Pink coolant?

[Joesson]

When I read the OP I thought that the coolant system had been run at some time with an unsuitable coolant or plain water causing subsequent discolouration of the coolant bottle.
But, then I noticed the date that @Pierce had joined, so whatever happened to the system it survived but left it's mark.