RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.

Created attachment 1473951 [details]
VNC desktop with wrong colours

Description of problem:
Colours of VNC desktop in vncviewer on ppc64 are wrong and there is also some repainting when moving window or select/highlight with mouse.

Version-Release number of selected component (if applicable):
tigervnc-1.8.0-9.el7.ppc64

How reproducible:
always

Steps to Reproduce:
1. $ vncserver :1
2. $ vncviewer :1

Actual results:
colours of desktop are wrong

Expected results:
colours of desktop should be correct

Additional info:
It is very probably endianness problem. Tested with vncserver running on ppc64 and x86_64, vncviewer on ppc64 had always wrong colours.
Via Vinagre colours of VNC desktop are correct.

Do you have chance to test on RHEL 7.5 with older Xserver and tigervnc? I would like to know whether it's a regression in RHEL 7.6 or whether this has been a problem for a long time.

Yes, I have. I will test it as soon as I will have ppc64 machine reserved. It should be at latest by tomorrow.

Wrong colours are also present on RHEL 7.5 with:
xorg-x11-server-Xorg-1.19.5-5.el7.ppc64
tigervnc-1.8.0-5.el7.ppc64
gnome <= 3.26

Fixed with tigervnc-1.8.0-10.el7.

Desktop colours now looks correct with tigervnc-1.8.0-10.el7.ppc64. Switching to verified.

(However there remains small issue, that popup with "Press F8 to open the context menu" is blue tinted. Filed that to bug 1618777.)

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHSA-2018:3059