Why roots do not look healthy anymore?

[Marmodac]

I have three, about 5 years old phals. During last a couple of months my roots become to change from green silver "fat" to dry, wrinkled, brownish.
They do not look healthy anymore.
Three months ago I re-potted all of them, removing rotten parts, and change the soil (orchid soil that looks like chunks of barks) - but it didn't help at all.
All leaves are green and looks healthy.
What happen to my orchids - what to do?
Thanks in advance

[reliablefool]

Some of them look a bit dehydrated (not unusual for aerial roots), but the first two pictures make me think maybe they are a little sunburned. Did you recently move them?

[RandomGemini]

They're not sunburned. I've seen this before. Those roots are picking up tannins from the bark they've been potted in. Basically, they're getting stains on them.

That said, the plant does look dehydrated. You need to water them about every 7 days. More often when you repot them in fresh bark. My guess? You didn't soak the bark overnight before you potted the plants.

It's ok. I did that too.

You will have to water it more frequently at first, the center of the media will dry out a lot faster than if you'd soaked the bark, but it's a bit late to fix that now, so just water more frequently until the bark starts to retain more moisture. Then you can go back to watering once a week.

[Marmodac]

Thanks for advices - I will try to watering now more often - to fix it.
Will se in few weeks how it works.