On Chroma Packs VS Old Recolour Skins
First of all, kudos Riot! The release of Chroma Packs is a brilliant idea and will definitely appeal to many players.
However, with recolour packs available I think it's about time all older recolour skins are retired to the Vault. I doubt anyone would buy one recolour and a (usually) outdated/ugly splash art for 520 RP instead of three recolours for 590 RP. Either this or lower their price to 390 RP.
Also, I think unlocking Chromas through Champion Mastery or, maybe, great success in a Featured Game Mode is a great idea and would motivate the playbase. Positive behaviour, sucess in Ranked 5v5s or them being ulockable to those with absurd amounts of IP are great alternatives, as well.
Cheers!