UI/UX expert for hands-on work with CSS/jQuery/Highcharts

We are currently rebranding an existing platform and the entire UI/UX needs attention. The application is a .NET SaaS application running on Microsoft Azure. We need help with the following key tasks:
- Come up with appropriate colour palette in keeping with the new brand
- Design CSS/jQuery/Html components to support all standard inputs such as buttons, menus, popups
- Review and improve existing dashboards, analytics and functional pages

Existing code base is MVC, using jQuery, jQuery UI, Bootstrap, C# backend, and responsive design.

We currently use both chart.js and highcharts although we are leaning towards highcharts as our preferred library for charting.

The new design will need to include all colours, layout and general components, as well as loaders, spinners and transitions.

We require a hands-on approach, so the deliverables will be working html/css/jQuery. We can either allow full access to the source code (would require someone comfortable with Visual Studio or VS Code) or we can handle the plumbing ourselves. The former is our preferred option.

This might lead to longer term engagements for the right person to help us as we continue to develop the platform and it's functionality.

Requires both light and dark mode support and will need to be responsive.

2 existing screen grabs are included to give an idea of the current look and feel.

This can be a phased project to make it easier:

1. Design colour pallette
2. Design key components
3. Design layout blocks
4. Design transitions
5. Implement CSS/HTML/jQuery changes to bring together into the app

It is probably sufficient to deliver for one key area, e.g. analytics, although there may be sub projects for other areas of the platform.

The right person will be able to show similar experience to a high standard on public facing web applications, should be creative as well as having solid coding experience in UI/UX. Any experience with C# and MVC is a bonus.