bulbs change colors?

[Acezwild]

So I run 2x250 watt radiums on a Galaxy dual ballast when it comes on during the day the 1 bulb within seconds turns purple after an hour or so of running it returns back to its original color is this normal?

 

[xrayrider]

I only run Radiums. I have noticed the color starting out more white the first few days, and gradually becoming more blue over the first month. I have also noticed that the 400 watt Radium in the center, run on a Coralvue electronic ballast looks a little bluer than the two 250 watt Radiums run on ARO ballasts, I use on the ends. The ARO ballasts have a hard time firing the Radiums, and don't always fire on the first try, so I will be replacing the ballasts soon. I am wondering if the color difference is from the bulbs on the 250 ballasts not getting quite enough current. I have never had one of my Radiums look purple, even for a little while.

 

[Acezwild]

both bulbs are running off 1 ballast. bulbs and ballast only been running for 2 months and the bulb turning purple only started last week but like I said its only doing it for about an hour a day and its happening 15-30 minutes of the lights coming on

 

[xrayrider]

That is really strange. I wonder if one side is not putting out full voltage until it warms up. You could test it with a Voltage meter to find out.