Is this a recent change? I'm also having a hard time. I can tell by toggling and looking for the number to go up and down. Very hard to tell by looking. Seems like the background colour takes the same values as the alternating post background colours, which are presumably intended to be subtle, and can be imperceptible depending on your monitor, eyesight. I imagine this confusion increases the number of calls to "like" and "unlike", increasing load on the server.