Time Tracker / docs / projects-and-automatic-colors

Projects and Automatic Colors

Project management, billing rates, tax tiers, and the deterministic mathematical FNV-1a color derivation algorithm in Time Tracker.

Managing Client Projects

The Projects tab organizes your operational domains:

  • Title & Description: clear labeling (e.g. Mobile App Redesign, Cloud Infrastructure Audit, Master Thesis).
  • Hourly Billing Rate: set your contracted hourly rate (e.g. $75.00/h). Non-billable internal projects can be set to zero or toggled off.
  • VAT / Tax Tier: specify local sales tax or VAT percentages (e.g. 20%) for automated tax estimation.
  • Archiving: when milestones conclude, archive the project to remove it from quick logging selectors while preserving full historical analytics.

The Color Engine: Zero Manual Color Picking

Selecting colors from endless palette grids is tedious and frequently results in poor contrast or duplicate hues.

In Time Tracker, project colors are derived algorithmically from their name:

How the Algorithm Works

  1. Deterministic FNV-1a Hashing: the project title passes through a custom FNV-1a hash function (avoiding platform-dependent hashCode()), guaranteeing the same title outputs the exact same color on iOS, Android, and across backups.
  2. Fixed CIELAB Perceptual Lightness & Chroma: perceptual lightness is anchored to $L^* = 62$ and chroma to $C^* = 78$. No project color ever appears too washed out or overly intense in comparison to its neighbors.
  3. Golden Angle Spacing ($137.5^\circ$): if two projects generate hues with an angular distance of less than $40^\circ$, the algorithm rotates by the golden section angle until it lands on the widest unallocated color space. This prevents visual collisions between projects.
  4. Frozen on First Save: as you type a title, the color badge previews the calculated hue in real time; once saved, the color is locked to the record so fixing a typo later does not alter historical charts.