I have few vector layers which I need to edit frequently. I'd like to be able to see through the layer when it's selected. I changed selection colour from both: Project Properties General settings and Options-->Canvas&Legend settings. For both of these I changed the opacity to 40% --> click OK --> save. It works for a while, but after I restart QGIS, the opacity is still set to 40% in both settings, but I can't see through the selection. So QGIS kind of thinks it's still showing transparent selection colour, but it actually is not. So is this a bug in QGIS or am I just missing something?
If I change the selection colour opacity from 40% to 39% and click "OK" the layer comes transparent again. I'm working with PostGIS layers, but this same problem occurs with shapefiles also.