Crassula muscosa var. muscosa has a yellow-flowering form as well as a maroon one.
When the five-pointed corollas of these flowers have been open for some time, the five anthers inside, initially also yellow, turn dark, having done their work.
The petal tips converge again now, amidst a general loss of floral colouring. The sepals become dominant again as during the bud phase, taking over from the petals and cover up the developing fruits (Smith, et al, 2017; iNaturalist).