scanloc: Phase Associator 2025.296#76adc9190

# Color Gradients

## Overview

A number of pre-defined color gradients are available for gempa modules. These gradients can be used when displaying color-coded values such as grids, spectrograms or heat-maps. The following is an overview of pre-defined gradients along with the name of the gradient which can be used in configurations. The gradients are grouped into:

- Full spectrum

- Dark to yellow

- Black and white

- Single color

- Three color

## List of Gradients

### Full spectrum

Gradients that use the full spectrum of colors.

#### Default

- Configuration name: `Default`

Figure 15: Example spectrogram using the “Default” color-gradient.

#### Spectrum

- Configuration name: `Spectrum`

Figure 17: Example spectrogram using the “Spectrum” color-gradient.

#### Circle

- Configuration name: `Circle`

Figure 19: Example spectrogram using the “Circle” color-gradient.

### Dark to yellow

Gradients optically resembling fire with increased energy beeing displayed by bright yellow tones.

#### BlackBody

- Configuration name: `BlackBody`

Figure 21: Example spectrogram using the “BlackBody” color-gradient.

#### Inferno

- Configuration name: `Inferno`

Figure 23: Example spectrogram using the “Inferno” color-gradient.

#### Plasma

- Configuration name: `Plasma`

Figure 25: Example spectrogram using the “Plasma” color-gradient.

### Black and white

For a maximum contrast there are these two gradients that just use black and white.

#### BlackWhite

- Configuration name: `BlackWhite`

Figure 27: Example spectrogram using the “BlackWhite” color-gradient.

#### WhiteBlack

- Configuration name: `WhiteBlack`

Figure 29: Example spectrogram using the “WhiteBlack” color-gradient.

### Single color

The single color gradients have the same benefit as the black and white gradients and are of a high contrast.

#### BluePurple

- Configuration name: `BuPu`

Figure 31: Example spectrogram using the “BluePurple” color-gradient.

#### Blues

- Configuration name: `Blues`

Figure 33: Example spectrogram using the “Blues” color-gradient.

#### PurpleRed

- Configuration name: `PuRd`

Figure 35: Example spectrogram using the “PurpleRed” color-gradient.

### Three color

Gradients allowing to distinguish more details than single colored.

#### RedYellowBlue

- Configuration name: `RdYlBu`

Figure 37: Example spectrogram using the “RedYellowBlue” color-gradient.

#### Parula

- Configuration name: `Parula`

Figure 39: Example spectrogram using the “Parula” color-gradient.

#### Viridis

- Configuration name: `Viridis`

Figure 41: Example spectrogram using the “Viridis” color-gradient.