Update search bar UI to match the design proposal

[allan-on]

Describe the feature request.
The search bar UI should be updated to match design recommendations by the design team

Additional context
See the design proposal

Acceptance criteria

• Update the search bar text to make the colour configurable
• Update the QR code icon and icon size

Implementation plan (For Engineers)
The plan for implementing the solution e.g. via a description or a check list for the various ordered tasks that will need to be completed.
i.e. Describe how you intend to solve the problem