Welcome to Android Central! On KitKat, if the wifi signal indicator in Quick Settings is red/orange, that means you're connected to wifi, but you're not connected to the Google servers. This could mean that there's a problem with your wifi network, or that there's a problem with the Google servers. If you're able to access other websites like Yahoo, but aren't able to connect to Google, then presumably it's the latter. Google servers can go down from time to time, but the downtime is usually pretty short.
Have you tried rebooting the tablet?