Board Game Arena

Hello,

in the https://boardgamearena.com/gamelist page, some games are framed with blue, others not. It's Lucky Numbers on my attached screenshot. There is not explanation about it.
What does it mean ?

Thank you

That means that there are open tables waiting for players. Possibly for the type of table green / real-time or yellow-orange / turn-based, that is selected at the bottom of each rectangle, but I am not sure if it is type specific.