Photon III? Not sure about the price, and apparently setting it to flash is more than simply pressing a button.
Otherwise, if you're inclined to modifying or self-building, you could try replacing the red LED with a yellow or amber one (might just work, if you're not too keen on getting maximum brightness). Or there are flashing (red) LEDs out there ('my' German electronics mailorder shop probably won't help you at all) which can be run directly from a simple DC source. I assume the RS thingy is something similar. The trick is, you can build any colour flashing LED with this beast by simply connecting a (visibly mounted) LED of your favourite colur in series with an (invisibly mounted) flasher LED (have to take care of the voltage range and dropout voltage of the 'normal' LED, but that's manageable).
HTH, bye
Markus