Coolant change from Orange to Genuine Volvo Green.
 

Hi guys,
I have a 2015 V40 D3 with the 5 cylinder engine. I have recently had the car Polestar optimised, so I wanted to make sure everything was in tiptop condition. I noticed that the coolant in the car was orange in colour and wanted to change it to genuine Volvo green.
I understand that the cooling system holds 8 litres but when I drained the coolant via the tap on the bottom left of the radiator only 4 litres came out. I understand that Im not going to all the coolant out the system.
I refilled with 4 litres of de-ironised water via the expansion tank and ran it up to temperature and then drained. I repeated this with another hot flushes before completing 2 more hot flushes but with genuine Volvo green coolant before refilling.
My question is, Would 4 flushes of the system be enough? As I have heard that if you mix orange with green coolant it can go to jelly?
Thanks