Question about stamping white balance

Hello,

I'm a beginner in Aperture and have the following question for which I haven't found an answer yet.

Let me explain what I did and where the problem rose:

I have a set of photo's (400+, RAW), all taken at the same location under nearly same conditions (oldtimer rally, outside, sunny weather).

I've adjusted the first image by choosing:

Exposure: 'auto'

White balance: 'auto'

White balance was changed by Aperture in (in the Inspector): Temperature & Tint and for both a specific value.

I changed the second image the same way.

Again Aperture choose Temperature & Tint for white balance and specific, but other, values than for the first image.

Fine sofar.

I lifted the adjustments of the second image:

Adjustments:

White balance : Auto White Balance

Exposure : Auto Exposure

Deselected everything but Adjustments for White balance and Exposure.

Selected image 3 until the last one and stamped them.

80% of the image's OK but for about 20% of the photo's, Aperture came up (in the Inspector) with "White balance: natural gray".

So I thought to be smart and changed one photo (White balance : natural gray) to Temperature & Tint.

Photo adjusted: OK.

If I lift the adjustments of this photo, Aperture shows:

Adjustments:

White balance : Temperature (4851.60), Tint (10.68)

Exposure : Auto Exposure

If I select this and use it to stamp all "White balance: natural gray" photo's, I have the problem that the 'stamp' also stamps the temperature and tint values where I want it, of course, to 'auto detect' these values as they are not the same for each photo for the best result.

Any solution for this?

Kind regards,

emeu1