Copy Scripts

Define p as something like script.Parent. Make another script that clones that script into all of the children of workspace.Frame3.

This isn't really a solution, but it does mean you won't have to change lots of scripts just because you want to try something different.

Functions

The code is the same thing for every p -- so we can just write a function.

function flash(p)
	while true do
		p.BrickColor = BrickColor.Red()
		wait(0.1)
		p.BrickColor = BrickColor.White()
		wait(0.1)
		p.BrickColor = BrickColor.Green()
		wait(0.1)
	end
end

then call that function for all of the children:

for _, child in pairs(workspace.Frame3:GetChildren()) do
	flash(child)
end

This won't actually work, though. That's because the first while loop won't ever stop. We can spawn new coroutines to solve this:

for _, child in pairs(workspace.Frame3:GetChildren()) do
	spawn(function() flash(child) end)
end

This will work (and actually works in a very similar way to just copying the scripts), but it isn't necessarily elegant.

One Loop

It depends on exactly what the pattern you want is. For instance, if you want them all to be the same color, you could do something like this:

function paint(bricks, color)
	for _, brick in pairs(bricks) do
		brick.BrickColor = color	
	end
end

while true do
	paint( workspace.Frame3:GetChildren(), BrickColor.Red())
	wait(0.1)
	paint( workspace.Frame3:GetChildren(), BrickColor.White())
	wait(0.1)
	paint( workspace.Frame3:GetChildren(), BrickColor.Green())
end

But that will be boring.

You could get finer control, though:

function update(brick, data)
	local name = brick.Name
	local number = tonumber(name:match("%d+"))
	-- Get the name in the brick
	-- In general, it would be better for the script to figure
	-- this out on its own, e.g., from a position
	local modulo = (data + number) % 3
	-- this will be 0, 1, or 2. It goes to the next one when you increase
	-- either number or data by 1 (and from 2 goes back to 0).
	if modulo == 0 then
		brick.BrickColor = BrickColor.White()
	elseif modulo == 1 then
		brick.BrickColor = BrickColor.Green()
	else
		brick.BrickColor = BrickColor.Red()
	end
end

function updateBricks(bricks, data)
	for _, brick in pairs(bricks) do
		update(brick, data)
	end
end

while true do
	for i = 1, 3 do
		wait(0.1)
		updateBricks( workspace.Frame3:GetChildren(), i)
	end
end

You could do of course a lot more.

It comes down to some "update" function. It needs to figure out, "at this moment, for this brick, what color do I need to pick?" Then you just need to call update with whatever information it needs.

Here's another update function, as an example:

function update(brick)
	local mag = brick.Position.magnitude
	local amt = 0.5 + 0.5 * math.cos( mag / 20 + tick() )
	brick.BrickColor = BrickColor.new( Color3.new(amt, amt, amt) )
end