Contrast ratio for button background color?

I am working with making a website WCAG II compliant. The designers are asking to use yellow buttons (specifically, #fcdb31) with blue text on top of them on white backgrounds.

• While the blue type on the yellow buttons DOES pass accessibility, do we need to be concerned that the yellow button color on a white background would not pass accessibility?
• Do button background colors even need to adhere to the same contrast ratios that the type does?

I don't want to unnecessarily change the button color if this is not something that needs to be done to be compliant.