[UI Improvement] change colors used by `/url save` command

[k3wixf4zkuor7vg1]

Expected Behavior

The information about downloading the file should be shown in white color. If download succeds, it should turn green and if it fails, then it should turn red.

Current Behavior

When downloading starts, the text is shown in red color, which suggests the error and this is confusing, because no error actually happens. After download finishes, the text turns white, which is neutral and doesn't indicate success nor failure.