Software with Color Replacement

PicoImageTool is a lightweight, portable application designed for preparing graphics for retro computers, embedded systems, and other hardware with limited display capabilities.

The application provides tools for image resizing, color quantization, palette management, and dithering, allowing modern images to be converted into formats suitable for low-color and indexed graphics systems.

PicoImageTool was originally developed in late 2025 as a small internal utility for Raspberry Pi Pico (hence the name) projects using VGA output.

The initial purpose was to convert PNG images into raw indexed graphics data while maintaining a separate, unified palette.

What began as a simple hand written project-specific tool has since evolved into a more versatile image conversion utility, with an improved interface, additional processing algorithms, and support for retro image formats. Currently its mostly vibe coded using Codex.

It's completely free and requires no installation.

Requirements: .NET 10 Desktop Runtime x64

Users can adjust the output size, reduce images to 8, 16, 32, or 64 colors, choose fixed palettes, enable dithering, and crop the source image. Manual color replacement supports undo and redo. Results can be exported as PNG at 1×, 2×, 4×, or 8× scale.

Swatchsmith is a batch palette-swap tool for pixel art. It loads PNG sprites, as single files or whole folders (sub-folders are kept), lists every colour they use, and lets you change colours one by one, lock colours, shift hue, saturation and brightness, or map a selection of colours to a palette by brightness order or nearest colour. Each set of changes is a variant, and every sprite is exported in every variant at once.

For parts of a sprite that share colours, a region can be painted on the sprite or loaded from mask images, so that a colour changes only inside or only outside it.

Palettes can be loaded from .hex (Lospec), .gpl, JASC .pal and paint.net files, or taken from a PNG image. The export is a ZIP with the recoloured PNGs, .hex and .gpl palettes for each variant, a palette lookup texture with Godot 4 and GLSL shaders for runtime palette swaps, and a project file for reusing the changes.

It is a single HTML file that runs offline in a desktop web browser; images are not uploaded anywhere. A free demo (3 sprites, 1 variant) runs in the browser. It is aimed at game developers and pixel artists who need team colours, enemy tiers or time-of-day versions of many sprites.