Conrail purple??

I've been looking at some photos taken of Conrail locomotives taken in the mid eighties and noticed quite a few engines seemed to be painted in a darker blue that bordered on a almost purple hue. Did Conrail change paint suppliers over the years?

Are they all different heritages, or do they go back to one particular road?

I shot some pictures of one of the ex-RDG GP40s... 3276 maybe... around 1995 and the blue on it was noticably darker. It appeared in Railpace about the same time, I'd have to dig it up to remember the number for sure.

But you'll note that the D&H GP38s in blue dip looked kind of purple when the blue faded and wore away and the LV red started to show through - it may be as simple as the CR blue going over say red primer giving it that odd cast.

As strange as it is I too have noticed Conrail Units in a Darker Blue than normal up till the mid 90's I want to say 1995 or 1997 was my last sighting of a C40-8W it was almost a Dark Royal Blue and it looked like a new paint job.

I noticed that when they repainted older units, like the C30-7A into the "Quality" scheme, it looked like a lighter shade of blue.
I think that the base color under the blue might make a difference. I have seen many units repainted over the years. Sometimes they do a cheap job, and do not prime the surfaces first. In this case, a Reading dark green, or a LV Cornell Red may throw off the new color. Sometimes, since the unit was not properly prepared, the blue might flake off, and you can see the previous color.
At work we have some of the ex B&M 300 series GP40-2s, in painted out Guilford colors. They just slapped on a coat of gray, an now the original B&M blue is showing.

It probably is in part different paint or exposure to different kinds of dirt. The other day I watched a train with two CSX GE C40-8 regular cabs. The one in the original paint the blue was bright, almost like an electric candy color; the other in a late repaint of the yellow nose scheme, the blue was visibly much darker.

Although there may be variations on the paint, fading over time, etc, I would suggest much of what you see relates to the pictures themselves.

Depending on the exposure, the blue paint may look a little lighter or darker. My experience is the Conrail blue paint usually looks a bit darker in the photos, and so it could take on an almost purple shade. Also, the films themselves may have variations on the blue color balance. You can usually see the Conrail blue looks a bit different between Kodachrome and Ektachrome, for instance.

Which of course doesn't explain the differences noted with the naked eye.

Conrail GP40-2 3279 I saw in person several times and it exhibited that purple tint mentioned above.

The purple could have been due to oxidation,the early CR paint was regular enamel from various suppliers. Lilly brand was the very 1st, IIRC.