Question

light colour clothes dash most of the heat that falls on them

Answer 1

reflect back.....in the place of dash

Answer 2

because light colour absorb less heat than dark color clothes

u can do a experiment also
take two iron or any metal piece one of black and other of white color
put them in sun for 2 hours

after 2 hours u will observe that the black metal is more warm than the metal with white colour