What you want to do is fill the selection using the Bucket Tool.
Once you've made your selection, select the Bucket Tool Shift+B, and then Shift+click inside the selection. This will fill the selection with the current foreground color.
What you want to do is fill the selection using the Bucket Tool.
Once you've made your selection, select the Bucket Tool Shift+B, and then Shift+click inside the selection. This will fill the selection with the current foreground color.