The UI Color Builder by Roman Shamin is an interactive tool designed to assist designers in creating harmonious color palettes using the OKLCH color space. OKLCH is a perceptual color model that aligns more closely with human vision, making it ideal for generating visually balanced color transitions. 
Users can define a starting and ending color by adjusting the Lightness (L), Chroma (C), and Hue (H) values. The tool then interpolates between these two colors, producing a series of intermediate colors that form a smooth gradient. This feature is particularly useful for developing UI themes, data visualizations, or any design requiring consistent color progression.
The interface includes sliders and input fields for precise control over color parameters, as well as a visual display of the resulting color steps. By leveraging the OKLCH model, the UI Color Builder ensures that the generated color palettes are perceptually uniform, enhancing the aesthetic quality of design projects.