Bling has always been in fashion.
Bling guns even more so.
Guns used to be exceedingly expensive, so adding stereo and turbo bling was always in the offing. Hot rods of their day, splash the cash, gets the puritans blood up...
I think some rifles can take some embellishment, be it higher grain wood or some engraving. However, they need to be of a quality and status to warrant it. The FWB Sport could handle some. Maybe today a AA TX. PCP's then carbon fibre looks snazzy, as does some graphics.
Once you have your factory offering, then a tuned up action and matched stock... where next? Sadly these one offs rarely add value to match the work done. Shotguns and Rifles can only hold some depending on the quality of the workmanship with only the very best holding parity. The value is generally the enjoyment of ownership and your own taste.
Some are a joy some I'm not quite so convinced with.
Anyhow, if you have the disposable income then go for it. Or buy some Hamilton bling diamond ear rings! Heck an all body tattoo. Think I know which I would prefer!