What is the name of the anime TV show where a boy can summon beasts with crystals/gems. It was on SABC 2. There was also a boy that could summon a purple turtle . I think the gems were blue, green, and red.
This is "Magi-Nation", a Canadian-Korean animated series.
Three thousand years ago in the Moonlands, the evil Shadow Magi Agram was sealed inside the planet's Core by the Core Glyph and the Dreamstones which provided its power. Now he plans to escape by using his Shadow Geysers to weaken his prison in order to bring the Moonlands under his control, and only a Magi known as the "Final Dreamer" can stop him. A young boy from Earth, Tony Jones, is summoned into the Moonlands as he is believed to be this Final Dreamer. He joins forces with the apprentice Magi, Edyn, and the Shadow Stalker, Strag, on a mission to gather the Dreamstones before Agram is set free. Using the Book of Elders, the three travel through the Moonlands while combatting the forces of Agram and gaining an ever-growing collection of Dream Creatures from the Moonlands that they visit.
The characters collect these "dream creatures" who are stored in gems once they've been defeated or befriended, and can later be summoned to help.
As you can see in this picture, one of the characters does have something that can be described as a purple turtle.