The daughters from Legbar mothers will lay blue or green eggs.
The daughters from Rhode Island Red and Marans mothers may lay brown eggs or green eggs, depending on the genetics of the rooster. Daughters of the Marans will lay darker brown eggs, or darker green eggs, than daughters of the RIR.
Many of the Easter Eggers from hatcheries are pure for the blue egg gene, and if he is like that, he will pass it to all of his chicks, and his daughters will lay green eggs (blue + brown).
But some Easter Eggers have only one gene for blue eggs, and if he is like that, only half of his chicks will get the blue egg gene and the rest will have not-blue. So you'd get half green eggers and half brown eggers.
And some Easter Eggers do not have the blue egg gene at all. If he does not have the blue egg gene, he cannot pass it on to his chicks, and all his daughters will lay brown eggs.
So if you want to be CERTAIN of getting blue-egger or green-egger chicks, either hatch only Legbar eggs or get a rooster that is known to be pure for the blue egg gene.
But if you want a variety of egg colors, then using this rooster with all of your hens will probably work fine. You will either get several shades of blue/green, or you will get blue/green and several shades of brown.
Once his daughters are laying eggs, you will know more about what egg color genes he has, so you can decide whether to get a different rooster for future years.