Put the #Q ClanSpray.VTF File in C:\Program Files\Steam\steamapps\SourceMods\sourceforts\materials\VGUI\logos
Put the #Q ClanSpray.VMT File in C:\Program Files\Steam\steamapps\SourceMods\sourceforts\materials\VGUI\logos\UI          


Then open up Source Forts, Go to options, Then Multiplayer then select the spray, it should work.