Last year we had so much fruit that I didn't have time to prepare everything. I ended up freezing large bags of plums and gages. I just washed them and put them in the freezer.
Two weeks ago my son asked if I could provide some desserts for my grandchildren's Christening. As well as making the usual trifles from soft fruits I had frozen, I took the remaining plums and gages out of the freezer, allowed them to defrost a little so I could remove the stones easily and then made crumbles. I overheard quite a few people saying how delicious they were.
So folks, if you don't have time to see to all your plums, then freeze them whole and they will not lose their flavour or colour. They had been in the freezer for almost a year too.