Check your SPI sticker on the inner side of your trunk lid, then take the thing to a store that deals with paint. One of those will be the lower paint colour for your car.
I checked the paint code. It's U518f, indicating it's an upper color in Medium gulf blue metallic. But no mention of a lower color. The car is stock that's why I want to keep the gray in the bumper the original color. It's a 98 GP Daytona...