1a) petals changing colour (6) p?s?e?
11a) Sack Bank employee (7) c???I?r
13a) Teach a tip about being indifferent (9) a?a???t?c
28a) Wrote of being enclosed (6) ?e?n?d
6d) Free flow (9) d?????r?e
21d) Be present at a race to the conclusion (6) ?t?e?d