This is a minnor issue, more cosmetic than anything to be honest, but I prefer to report it : The LibreELEC addon does'nt apply the theme/color used in Estuary skin, it keeps the buttons blue, rather than using the setted colors.
I'm sure you know to change the color for the skin, so I won't add any step to reproduce
I have the problem with both of my systems (R.PI 1 or R.PI 2), so it seems not related to the hardware. But all of them were previously OpenELEC 6.03, so it might be something related.
Should you need any logs if you can't reproduce the issue, please feel free to ask, but I feel you won't neet them
All the best.