Circuit to detect two sequential pulses
so, a D type flip flop with red on D input blue on the clock and blue on the  inverted reset input.

eg: SN74LVC1G175

you will need need to stretch the red pulse a bit if you want to trigger off the pulses you have drawn.

a retriggerrable monostable like SN74LVC1G123 is probably a good choice as its power requirements are signioficantly less than thoise of a 555