Hefeweizen brewing and Decoction mashing

I am brewing a hefeweizen using a single decoction. I am using a cooler for mashing and using hot water infusions. The first batch I did, I used 30% of the mash for the decoction boiled it and mixed it back in with the resting mash. Then I used water infusions to get the mash to 158. When I was about to lauter the mash, the color was grayish and not resembling a golden color in anyway.

Anyone have a suggestion to rememdy my problem?