Tipping Point? It's where shoes may be fashionable pale yellow colour (4,5)
I believe the answer is:
last straw
'tipping point?' is the definition.
'where shoes may be fashionable pale yellow colour' is the wordplay.
'where shoes may be fashionable' becomes 'last' (tool on which a shoemaker may fashion shoes).
'pale yellow colour' becomes 'straw' (I've seen this before).
'last'+'straw'='LAST STRAW'
'it's' acts as a link.
(Other definitions for last straw that I've seen before include "Something tipping the balance" , "drinker was lucky to get?" , "Start laws (anag) ? breaking point?" , "The final irritation that stretches your patience beyond the limit" , "ultimate irritation" .)