why the exhaust colour changes to Bluesh and Red when the bike is ripped during the running in period....(chrome exhaust)

is it because the engine produces more heat during the break in period????

cuz once the running in is done it never changes irrespective of how hard bike is Ripped then......

cuz after riding my Suzuki FIERO (sold it now) for 18kms non stop in full throttle (105kmph) the exhaust turned blueish and red from the cylender head side but after it cooled off it came back to normal colour....