I’m testing (s922x\a311d - VIM3, N2, AM6, s905x2 - x2cube etc) all 5.4.x kernels and the most recent versions of next, when using u-boot-2015 (with a build date of July-August 2019), everything works without problems. All colors are correct in all LE and Armbian builds. The problem only appears when switching to the latest version of u-boot-2015 (which AML broke and did not fix).
What firmware do you have installed in VIM3 ?
I have a long time ago installed the LE version in eMMC and so I do not know exactly the firmware version number in which the normal u-boot is 2015, but here is the output of the u-boot version and the output of the kernel version 5.4 , with which I have no problems with not the correct Kodi colors. The only thing that in this version (with this kernel 5.4) does not work DEMO PVR (when playing a test clip, the whole screen is green). By the way, I rolled back to the Assembly with the 5.3 kernel, everything works there and with the new u-boot-2015 and DEMO PVR works.
U-Boot 2015.01-g11ea16c-dirty (Jul 04 2019 - 09:44:47)
LibreELEC (community): devel-20191025102633-6e9040d (AML.arm)
LibreELEC:~ # uname -a
Linux LibreELEC 5.4.0-rc3 #1 SMP Fri Oct 25 11:03:42 MSK 2019 aarch64 GNU/Linux