Different look of the map on full screen and when embed on website with OpenLayers

I use vector map and OpenLayers to display it. When I enable fullscreen mode, my map style changes and is like in the editor in MapTiler. When the map is displayed in a smaller window, its style is different - brighter. What could be the reason?
Full screen

Zrzut ekranu z 2018-09-27 10:22:11.png

Map on site 

Zrzut ekranu z 2018-09-27 10:21:51.png

1 reply

The background color was replaced: rgba(245, 245, 245, 0.92), by this: rgba(227, 227, 227, 1) it's the same, but color alpha is 1. Alpha is not recognized correctly by OpenLayers.