On the Blue scale...
Last Nov, pool turned us a nice shade of purple
Last 2 weeks, was down to a good looking royal blue!
Yes they are cold if you go for the tip toe in approach, in which case you'll never make it any further than your ankles. My advice - dive in, take the shock and get out quickly. The dive in again and stay in. Found this to be the best way to get your body temp low enough to aclimatise. After that, had no problem staying in the water, just got cold when you did step out again into the chilling breeze
Good luck
Foz