Simple problem missed by many building their first standalone. The arduino IDE utilizes the serial DTR or RTS control signal to trigger a reset on the target thus activating the bootload that can then let the IDE download the sketch to the target. You can usually get by it by using the manual reset button on your target chip but it has to be timed correctly just at the time the IDE is starting the upload operation. The better option is to see if your serial cable makes the DTR or RTS control signal avalible and wire that through a series .1ufd cap to the target's reset pin. Are you sure the green wire is the DTR or RTS signal?