Gerhard Schroeder does not see the funny side
Friday's hearing lasted 10 minutes, and the Hamburg court said it would deliver its judgment on 17 May.
Earlier this year the DDP agency quoted a woman image consultant suggesting teasingly that Gerhard Schroeder, aged 58, should admit that he dyed his hair to keep it looking dark.
Mr Schroeder won a court injunction to stop DDP carrying further reports about his hair, but it ignored the ruling.
Lawyers for the 58-year-old chancellor said that since the injunction had been broken, "we are obliged to sue".
Mr Schroeder's conservative political rivals have made much of the row, one claiming that "someone who touches up his hair also touches up statistics".
DDP says it could not accept the court injunction, because it would have become the only German media outlet unable to report on the matter.
Its editor-in-chief, Bernd von Jutrcenzka, has argued that the injunction was unnecessary because the agency published a retraction.
He has also pointed out that the chancellor took no action against the image consultant, Sabine Schwind von Egelstein.
'Very natural'
"I would know if Gerhard Schroeder was colouring his hair," he says.
He insists the chancellor's hair is "very natural. He looks great."
Udo Walz is even more specific. "If you go close, like I do, you can see that he has some grey hairs" underneath the thick mat of dark brown locks.
But Udo insists the grey hairs just stay there, and are hard to see.
His written testimony to the court, along with that of Mr Schroeder's former hairdresser in Hanover, was submitted to the court by Mr Schroeder's lawyers.
Mr Schroeder has a reputation for being more laid-back than most of his compatriot politicians.
But many media reports in Germany imply that on this issue his sense of humour has taken a holiday.
A court ruling is expected soon, at the latest within three weeks.