@SylviaDavies I'm just curious, has your outer leaves (not just the flowers) ever turned a beautiful deep pink, but still has the pattern of the leaves still, but even the inner deeper green gets glazed over with pink too? I've had my plant for 10 years or so, and mine has just started doing this the past 3 months or so in areas of the plant turning very deeply pink, and hints of the pink are showing slightly around the edges on many other leaves too. It's really neat, and I am just curious.
@johnst my advice would be to not cut it back completely because after 10 years my leaves this year just started to turn a beautiful pink probably because I let it grow out is the only reason I can think of. It's so pretty now and I hate to cut it back at all but I probably will a little bit to keep it under control but not all the way back that's for sure. Hope that helps :-)