I'm a little suspicious.
Clarification: there's no way anyone would go to the trouble of painting these benches green, just as the pretext for a "wet paint sign" joke. That's hard work - and a job well done! I don't suspect the painters, whoever they may have been. I salute their diligent efforts. But maybe the prankster came along later, and put the signs that had been left (on the wall, perhaps?) in the paint - just to be a "cut-up"! Well that's exactly the kind of bullshit "practical joke" I can't abide!
It's been a while since I had to drag out the "not even funny" tag, but this little stunt here warrants it - en spades.
Damn it, I wanted that to come across all masculine and fancy by putting the Spanish of "in spades." But apparently, in Spain, they call a spade a spade. Which speaks well of them I suppose - but it shoots my efforts to shade the capper of this post with a bit of European romance-language exoticism right in the ol' puedo.
Perhaps if you go back and re-read it, mentally pronouncing it "en spah-dez." That could make the needed difference! Please try it, and let me know in the comments how it worked out for you.