Monsieur Tillier hips... when are they ready?

On my small plant of ‘M. Tillier’ I have a single hip of ‘M. Tillier’ x R. bracteata. The rate at which my hips are disappearing to animals at the moment has me concerned for its welfare. I’ve put a small draw-string bag around it incase it falls and it is starting to develop a purple flush to one side. I have be advised that Tea hips take longer to mature than most and it was a late cross made around the beginning of March (making the hip around 90 days old). We are in our winter now so I was thinking the purple flush on it was maybe a response to the frosts we are getting now and not maturity. The hip is not very big (looks like maybe half-a-dozen at most) and it is the only hip on the plant (if that makes any difference in terms of resource allocation etc, etc). I was wondering whether ‘M. Tillier’ hips change colour to orange/red when mature or do they stay green? My ‘Lorraine Lee’ x ‘Mutabilis’ hips stayed green despite the hip being close to 6 months old at harvest. I really don’t want to stuff this one up.

BTW… the Tea book says ‘M. Tillier’ hips should go orange… but then it also says my ‘Lorraine Lee’ hips should have gone dark yellow.

If it were me, I would leave it on the bush until it did develop the color it is supposed to, whatever that is…or else until it actually started to show signs of abscissing (lightly flick it to see if it drops easily)… I would also consider caging that plant if it is small and feasible, to protect it from hungry Tasmanian critters.