Update Theme to align to brand styles

[0xRowdy]

If the design is changed, the following resources should be referenced.

https://www.edgecity.live/
https://www.figma.com/proto/BF0zWPcKFLQ7K1fjV4C3wU/EXTERNAL-Hypercerts-brand-guidelines?page-id=108%3A8706&node-id=108-8739&viewport=857%2C385%2C0.5&t=JRftKtFef5gSl58H-1&scaling=min-zoom&starting-point-node-id=108%3A8739