Just an update here, after discussion with the project manager we decided to take down those 3 courses, use some of the lighter ones for the non visible sides of the building then we bought a new wrapped palette of drier bricks, and i chose the bricks individually to complete the front which have a better mix of red/yellow/black. Maybe there is some truth that these bricks were very wet and would of eventually dried lighter, but that would be too risky I thought, also they were all deep reds, and no yellows in the mix.
Unrpedictable little things these Heather bricks!