For those saying this is probably just the devs being lazy... Well, they took the effort to write these two lines of CSS, and took the time to make sure they displayed as the exact same color.

    input:checked+.slider {
      background-color: rgba(18, 107, 255, 1);
    }

    input+.slider {
      background-color: rgba(18, 107, 255, 1);
    }

So there was effort to make both sides blue, whether that was incompetence or intentional, the design itself is still an asshole design and should be shamed :) Good toggle switches can be found all over the web in seconds!