We are experiencing a reproducible image-editing issue in which returned images have a slight pink color cast.
The problem started after the transition from the previous Preview model to the current Image model.
Instead of preserving the original neutral color balance, the edited result comes back with a subtle pink tint across the image.
This issue occurs during image editing / image transformation workflows, where an existing image is provided and the model is asked to modify or redesign it.
We have observed this behavior with:
- Nano Banana Pro
- Nano Banana 2 (Gemini 3.1 Flash Image)
The issue is reproducible through both:
- Replicate
- Vertex AI API
This suggests that the problem may originate in the underlying model or image-processing pipeline rather than being limited to a single provider integration.
The pink tint is visible at 2K and 4K resolution.
At 1K, the issue is not visible or only barely visible.
Expected result
The edited image should preserve a neutral and consistent color balance unless the prompt explicitly requests a color shift or stylized grading.
Actual result
The returned edited image has a subtle but noticeable pink color cast, even though no pink tone, warm color shift, or stylized recoloring was requested.
Conditions under which the issue occurs
- Access path / provider:
- Replicate
- Vertex AI API
- Affected models:
- Nano Banana Pro
- Nano Banana 2 (Gemini 3.1 Flash Image)
- Workflow type: image editing / image-to-image editing
- Resolution:
- 2K → pink tint visible
- 4K → pink tint visible
- 1K → not visible or barely visible
- Output format: can be tested with PNG and JPG/JPEG
- Model transition context:
- issue began after switch from Preview to Image
Example description of the issue
We provide an input image and request an edit or redesign.
The returned image shows a slight pink cast across the image, even though the prompt does not request any color shift.This affects the overall neutrality of the result and is especially problematic for product and commercial imagery, where color fidelity is important.
Example prompt
Replace the shoes in this image with the shoes shown in the reference images. Keep everything else exactly the same.
Steps to reproduce
- Provide an input image for editing.
- Run the edit workflow through Replicate or Vertex AI API.
- Use Nano Banana Pro or Nano Banana 2 (Gemini 3.1 Flash Image).
- Request a normal edit without asking for any color grading.
- Generate the result at 2K or 4K.
- Compare the returned image with the expected neutral color balance.
- Observe the slight pink tint in the output.
Additional observations
- The issue appears only after the transition from Preview to Image.
- It affects multiple models:
*
Nano Banana Pro
*
Nano Banana 2 / Gemini 3.1 Flash Image - It affects multiple access paths:
*
Replicate
*
Vertex AI API - The issue is visible in 2K and 4K outputs.
- At 1K, the issue is not visible or only minimally visible.
- The problem seems related to edited outputs, not necessarily to every generation workflow.
- The pink cast appears even when the prompt does not request any warm tone, pink styling, or color shift.
- This suggests a possible issue in the color processing, rendering, or high-resolution output pipeline.
Regression information
We started noticing this issue only after the switch from the previous Preview model version to the current Image version.
Request
Please investigate whether this is a regression in the image-editing pipeline that introduces an unintended pink color cast in edited outputs, especially at 2K and 4K resolutions.
Because the same issue occurs across both Replicate and Vertex AI API, the root cause may be upstream in the underlying model or image-processing pipeline.
Examples:
Please note that the bottom image has gone through multiple generations (3 regenerations). The pinkhue shift that is visible here is therefore exaggerated, but it shows the underlying problem because the image got pinker with every generation. With a single generation the shift is not as strong.