Google Funding Choices - not enough contrast between colours

I am trying to add Google Funding Choices to a website, but when I am trying to save the layout, I am getting an error notification: Not enough contrast between button colour and font colour. Select different colours.

The selected colours have enough contrast and they look good. What should I change to make it work ? What colours are acceptable ?

Hi,

Background colour and font colour of the buttons displayed in messages must differ enough to be easily readable. When saving the settings there is a contrast ratio calculated to check whether there is enough contrast between the colours.

To match the requirements for a contrast, you have to decrease colour luminance / lightness or increase colour saturation. From my experience, it was enough to set colour luminance value below 115.