Slivering is when air bubbles stay trapped under the decal causing a silvery appearance when applied to a non smooth surface like flat paint. Never spray the clear parts without masking the parts you don't want paint on, including a clear coat because yes it will ruin the clear plastic. Here's a link with some good info for you to read and youtube videos really helped me out when I started back at this hobby. https://www.cybermodeler.com/tips/painting.shtml