Practical ‘lightest’ shade of grey for contrast with white

I often use a light shade of grey such as rgb(242,242,242) in my designs to provide a subtle contrast to white, e.g. for the background of alternating rows in a table.

I can easily distinguish between this grey and white on my display (a 27" 4K) but on other displays this is not always the case, which reflects badly on my designs and could impact user experience.

Reasons might include badly calibrated / poor quality displays.

Assuming all accessibility standards have been met, is there a 'lightest' shade of grey that:

• Provides a contrast with a white background
• Does not significantly impact the legibility of dark foreground text
• Will be reliably displayed for most users under normal conditions