useBreakpointValue

const breakpoint = useBreakpoint()
const bg = useBreakpointValue({
  base: "red.500",
  "2xl": "pink.500",
  xl: "blue.500",
  lg: "green.500",
  md: "yellow.500",
  sm: "purple.500",
})

return (
  <Box
    bg={bg}
    p="md"
    rounded="md"
    color="white"
    transitionProperty="all"
    transitionDuration="slower"
  >
    The current breakpoint is "{breakpoint}"
  </Box>
)