Thanks a lot for the info! This particular remote and IR receiver indeed generate very odd key codes. LibreELEC ships with a translation layer (via eventlircd) to translate some of these codes into usable ones. The 4 colour buttons seem untranslated though.
You should be able to remap the colour buttons with a Lircmap.xml file (in /storage/.kodi/userdata). eg this should get you the standard red/green/blue/yellow kodi button codes, which you can then assign via the keymap editor
<lircmap>
<remote device="devinput">
<red>KEY_TUNER</red>
<yellow>KEY_AUDIO</yellow>
<blue>KEY_GREEN</blue>
<green>KEY_SUBTITLE</green>
</remote>
</lircmap>
If you prefer you can also map the red button directly to kodi's video button via <myvideo>KEY_TUNER</myvideo>
To change the behaviour of the power button (which fortunately seems to use the standard KEY_POWER keycode) it's best to create a remote.xml file in /storage/.kodi/userdata/keymaps eg like this to change the power button to suspend
My personal preference is to get the shutdown menu displayed which you can get with <power>ActivateWindow(ShutdownMenu)</power>
so long,
Hias