Perhaps something akin to cell RS gold shading like in LoZ: Wind Waker? It'd certainly have helped to differentiate it in the modern market. Most people I've ever talked to about Runescape who are lapsed players bemoan the modern art style as generictbf, one guy a few years back seemed to really like it.
The tutorial is unrepresentative of the game, even if it's prettier. Sorry Jagex, I know you've worked on it plenty. But it's simply not as straightforward as the original Tutorial Island and it'd be better served as a quest.
It further alienates returning players and gives new players a completely different impression of what Runescape is compared to what you present it as. Up until you escape Burthorpe, it feels like you're playing a completely different game.
Burthorpe is packed and busy, whereas Lumbridge is spread out cheap OSRS gold and leaves you to your own devices. I've seen posts about player retention but honestly. Why reinvent the wheel at all? It'd have probably been cheaper and more effective to introduce EoC elements into the original tutorial than to go to all this trouble.