I fitted an extra radiator in my house the other day. Some of the
existing water leaked out into a bowl during the process. I was
surprised at the colour: like oxtail soup (though not as thick!) or
like stewed tea with only a drop of milk in it. Is that normal?

I think I drained and flushed the sytem about two years ago, and
refilled it adding some Fernox descaling ant-corrosive aditive.

TIA,

Ed Boone