A color chosen rather than needed
Brown and green get used because a scene demands them. Purple gets used because a child wanted it, and that turns out to matter just as much. It is the shade of the invented creature, the flower that does not exist, the sky in a picture made at bedtime. In our experience the colors children choose for themselves are the ones that produce the longer sessions.
It is a soft violet rather than a hard magenta, so it sits agreeably beside the pink and does not fight the green. Kneaded with white it goes to lilac, which is almost impossible to buy and very easy to make.
Working with it
The same light foam texture as the rest of this shelf: immediate give, no crumbling, joins under finger pressure. Children who find earthen clay too stiff to shape get on with this straight away, which is most of why the shelf exists.
Roll it thin for petals and leave them to firm up slightly before assembling a flower, or the lower petals flatten under the weight of the upper ones. Ten minutes of patience buys a far better result.
Drying and keeping the rest
Petals and other thin work dry overnight. Anything solid wants a day, and thick pieces should be hollowed. Press the air out of the bag and seal it after every session; stored cool and closed, the remainder will still be soft months later.