Low power circuit (circuit playground classic - arduino)

My circuit is consuming 18mA at standby and 24mA when activated (LEDs twinkle) - at 3.3V based on the code that I wrote. I want you to use my code and introduce low power techniques such as sleep mode, low power mode, PWM, Gamma correction, etc, to reduce power consumption. I want to document the progress of the power consumption from the initial value of 18mA at standby (24mA when activated) to the lowest possible - ideally around 5mA (while of course ensuring the circuit works for its purpose). It is worth noting down that the circuit works by taking the value of the integrated light sensor (and if below a certain level) then the integrated LEDs will be activated by any movement that is picked up by the accelerometer. The purpose of it is to allow pedestrians (especially children and the vulnerable) to be more visible during night time (dark) in order to reduce accidents and fatalities. This device is going to be worn on the wrist as shown on the attached video.