Got a question about colour balancing two cameras.

I'm shooting with a xf100 and xa20.

I've tried manual white balance and both camera's give different K readings e.g. 6200 k and 6500 K

Would it be better to white balance to sunlight (5600K) to get the same whites, or allow camera's to manual set even though each gives a slightly different reading?

I'm using 6500K cool daylight balanced fluros indoors

The more important question is do the images look the same? It's not unusual for colour temperature readings to differ slightly between cameras, you need to compare the outputs of the cameras to see if they'll cut together.

You should also ensure that the your card is in the same lighting when doing a white balance with two cameras.

Allow both cameras to manual set? You mean auto white balance? Can you describe how you are physical doing it? I assume you have both cameras framed on the same card, filling the screen when you press the button?

Even if both cameras are pointing at the same card and give a different setting when they balance, what do they see? If you have a couple of cables and a monitor with two channels, you can compare them. I'd bet they could be giving exactly the same output colour, but the lenses may have slightly different optical properties meaning slight differences to the internal adjustment.