I can't spot any AGP slots, mate.
The red ring is PCI Express Ч16, yellow and green are for standard PCI (32-bit) and the blue one is for PCI Express Ч4.
True, an AGP slot should be bigger. Though i once had a combo board with both PCI-E and AGP. So they really exist, but PCI-E is often capped at 4x while providing a real 16x slot.