This scene was saved in Corona 1.5 that had wrong order of color mapping operations, resulting in unexpected color temperature behavior (blue tint). You should switch to the new order and save to get more expected behavior. 

This message appears only when rendering a scene, which was saved with Corona Renderer 1.5, and then opened with Corona 1.5.1 or newer.

In Corona Renderer 1.5, a problem with wrong color temperature appeared due to new color mapping operations order. This resulted in shifted color temperature of the rendered image compared to the output produced by Corona Renderer 1.4 or older. If the scene was originally saved with cold color temperature, then it would get even colder (more blueish) when rendering with Corona 1.5. Likewise, if it was saved with a warm color temperature, it would get even warmer (more reddish) in Corona 1.5 - see examples below.

Corona Renderer 1.5.1 (hotfix 1) was released to solve this issue. If a scene saved with Corona 1.5 is detected, then this error message appears, allowing you to switch to the correct order of color mapping operations, which should make the color balance exactly the same as when rendered in the older versions of Corona.

Switch to correct order » - This automatically fixes the color temperature issue - after pressing this button, white balance in the rendered image should be exactly the same as in Corona 1.4 or older. If there is still any difference between the color temperatures, please contact us.

To access the switch manually:

  1. Go to Render Setup > System and click the "System Settings" button at the top of the window
  2. In the new popup window, check "Enable devel/debug mode"
  3. Go to Render Setup > Performance > Development/Experimental Stuff rollout
  4. Under "Basic configuration" check "Use legacy 1.5 Color balance"

"Use legacy 1.5 Color balance" tooltip:

Reverts Corona tone mapping to the original 1.5 version, where white balance was applied at the end of the chain, resulting in blueish tint when combined with highlight compression. Only provided to ensure compatibility when loading old scenes, will be removed in the future.

Note: this fixes color balance issue only. There might be some additional differences between images rendered with Corona 1.4 or older and Corona 1.5.1, mainly due to different contrast algorithm.

See: What might change if I open an older scene in Corona 1.5?


White balance, from left to right: 4500K, 6500K, 8500K. Exactly the same scene rendered with:

Corona Renderer 1.4:

Corona Renderer 1.5:

Corona Renderer 1.5.1 with the switch applied: