Iphone
Can I bring my brand new iPhone 8plus 64 GB Space gray model to Apple and swap for silver model with the same specs?
http://www.apple.com/legal/sales_policies/retail_us.html - For iPhone returns, you may return your undamaged iPhone with its included accessories within 14 days of purchase for a full refund. Here’s the important part: returning your iPhone may not automatically cancel or reset your wireless account; you are responsible for your wireless service agreement and for any applicable fees associated with your wireless account. Please contact your provider for more information
If you're too late for a return:
Trade-Up program - https://www.apple.com/iphone/trade-up/ - "Just trade in your eligible smartphone, and then use the credit to lower the full cost of a new iPhone or to reduce the monthly payments with your carrier." Not available in all countries. UK program: https://www.apple.com/uk/shop/iphone/iphone-upgrade-program