RIP-0017 Remove theme from on-chain, move it to metadata spec

[Yuripetusko]

• author(s): Yuri Petusko
• contact: @Yuripetusko
• RIP type: upgrade

RIP Summary

We shouldn't be saving theme object on-chain and instead adding it as a property to add to metadata and saved on IPFS

RIP Details

There's no point, and often not possible (like on evm/substrate) to save theme object arbitrary shape on-chain, we should instead add it as optional property to save alongside other metadata properties and write a guide for consumers/clients on how to parse and use with different base types, starting with SVG base (catalog).

Examples

const metadataFields: Metadata = {
  mediaUri: 'ipfs://ipfs/xxx',
  externalUri: 'https://singular.app',
  name: 'Rare #333,
  description: 'Very rare bird',
  theme: {theme_color_1: '#dd6195', theme_color_2: '#fdb453', theme_color_3: '#370842', theme_color_4: '#8f2386'}
};

Open Questions

Questions for the community, to still be discussed.

Prior work (optional)

Citations, acknowledgments for inspiration, projects this RIP is emulating, etc.

Impact

We don't have many existing NFTs which use theme so this shouldn't impact many