In the Library select all the images in the grid and then go to the Quick Develop Tab. Click once on the outside right facing button (with two arrows) to update all selected images. You can then go to the basic tab in Develop to check the temperature slider setting.
Thanks, I did this, but the two arrow button goes +500 on the temp.
I need +20 or +50
The arrow increments are too large.
It will add 20 to the previous setting.
The inner button will add 5 - try clicking four times.
Ok, so here is what it is doing to a single image.
Select and image which has a colour temp of 2800
Using the quick develop console I click a single arrow to increase the colour temp.
The amount increases to 2925
Click it 4 times and it goes to 3203
Either I'm misunderstanding you, or there's a lack of understanding of the problem I have.
The quick develop console is fine, but the amount the arrows change things is too great.
OK I can see what you are saying. It's not exactly clear as the History steps just say make warmer.
Strangely I was able to do it on a batch of exported jpegs where the starting value was zero but not on raw files with a definitive K value.
"Relative Adjustments" are still not implemented in LR 6/CC:
There are some plugins available that will allow applying relative settings and presets, but you can also do this using the Graduated filter:
In LR 6/CC the Temp slider changes Color Temperature by 50° with a setting of 1.
It's not the +20 increment you are looking for, but it's a very small "visual' change. You will need to 'Sync' the Graduated Filter adjustment across all images.