Ok the map rule is:

Orange squares are Low Gravity Squares. Characters occupying Low Gravity Squares may move per standard movement rules. When a character occupying an Orange Square is hit by an attack, they are knocked back equal to the damage taken.

Does this effect colossal figures as well since it is a map effect? I know that normally colossal figs don't take knock back but does the map rule allow for them to be due to low gravity?

thanks

Nope. The rules rule.

In case "the rules rule" isn't clear enough, any effect that normally prevents knockback will continue to do so on the space racetrack map.