Whisk together coconut milk and curry paste in a slow cooker. Add chicken, bell peppers, onion, and garlic.

Cook on Low, stirring halfway, until chicken juices run clear and the vegetables are cooked through, 4 to 5 hours.

Meanwhile, bring water and rice to a boil in a saucepan. Reduce heat to medium-low, cover, and simmer until rice is tender and water has been absorbed, 15 to 20 minutes.

Serve chicken curry over cooked rice. Garnish with coconut and raisins.