# GPT Image Hub prompt

## Ishihara Color Blindness Test Plate
- URL: https://www.gptimagehub.com/library/ishihara-color-blindness-test-plate
- Generator URL: https://www.gptimagehub.com/generate?promptId=oss-ym-g2-13946
- Markdown URL: https://www.gptimagehub.com/api/agent/markdown?path=%2Flibrary%2Fishihara-color-blindness-test-plate
- Category: Infographic / Education
- Model: gpt-image-2
- Aspect ratio: 1:1
- Style: graphic-design
- Tags: ishihara, color blindness, optical illusion, pointillism, medical chart, pattern
- Updated: 2026-10-28T01:59:28.098Z
- Created: 2026-10-28T01:59:28.098Z

Generates a classic Ishihara pseudo-isochromatic test plate with a hidden number. Customize the embedded number and dot color palettes to create different optical test patterns.

### Full prompt
```text
An Ishihara color blindness test plate featuring a large circular field densely filled with randomized dots of varying sizes. The background dots within the circle are shades of [olive green and yellow]. Embedded in the center is the number [67], composed of contrasting dots in shades of [muted red and coral]. The area outside the main circular plate is filled with darker, muted brownish-green dots, creating an authentic medical optical illusion in a seamless pointillism style.
```