T 013 Swiss Flag
The most important part of filter editing is connecting the effects into a chain that defines the rendering process.
With only a Flood added it's listed at the top row.
The current editor lists the filter primitives added one after another. The bottom line of that list will be rendered on screen.
Note that just by adding new filter primitives to the list, they won't necessarily create a chain from top to bottom.
You need to connect them in a meaningful order.