to help properly you will need to catch and contain the pigeon , perhaps if you give your location someone on site may help thanks for you time in trying to help this pigeon
grizzle to grizzle do go whiter so pairing to a chequer or blue stops them getting too white however this can reduce the number of grizzles been bred one nest will have one blue and a grizzle on and next may have two grizzles
i have a similar cock bird with a frill its not a trait of the Kirkpatrick i would suggest its a cross with Delbar or Jansen my cross is a Jansen but also have Delbar as well