The open-air exhibition and workshop attracted locals exhausted by a conflict with no end in sight.
"I came here with my family to express how fed up we are with the way we're living because of the war," said Fouad Sharfeddin.
"This event gives us a breather and hope for a return to a normal life."
The war between pro-government forces and Shiite Huthi rebels who control Sanaa has devastated Yemen and pushed it to the brink of famine.
Since a 2015 intervention by a Saudi-led coalition, fighting has left at least 7,400 people dead and wounded 40,000, according to the United Nations.
"Yemenis are lost," Sharfeddin's wife Maryam said. "We try to help the kids relax, even a little, by painting to express the feelings of repression we have inside."
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A young artist wrote "no dreams" next to a stencil of a child, then sat on the pavement under a mural of three heavily-armed soldiers.
Another painted a bouquet of red roses next to a soldier pointing his weapon at a collection of hearts.
The event was organised by an artists' collective let by Mourad Soubaye, in defiance of the rebels who control the capital.
"This is a day for peace, against violence, war and the current situation," said Soubaye.
It followed another rare demonstration, a three-day women's sit-in protest against the war.
The artists wrote a leaflet addressed to Sanaa residents, saying they did not take a position in the conflict.
"While war divides, art unites beyond borders and barriers," they wrote.
They called their open day "an opportunity for people express their hope for peace and their rejection of violence."
"All we want is to get out of the crisis," Soubaye said.