Color shift of Metal halide

[pbyrmartin]

I recently replace my MH lamps, but recently I notice a color shift from blue to yellow
The bulbs are 175 watts 14k made by blue line
They will change to yellow for about 30 minutes then change back to blue
What I am thinking is that the fans has something to do with it
When ever I lift the canopy the fans are not blowing directly on the bulbs so the temp is not the same.
Is this normal.

 

[glxtrix]

is this at first when you start them up? Or anytime durring the day when the fans are on?

 

[pbyrmartin]

it started happening when I lift up the hood for more than five mintute

the center lamp not doing this
just the two outer ones with the fan blowing on then

I am trying to se if I have some bad lamps

they are only seven weeks old