Keeping the reset pin pressed for 30 seconds, logically does not make sense. However, I did try the entire 90 seconds cycle and it is still flashing.I can understand why you'd think that but its a physical button that has time sensitivity built into it, which is why when pressed for 1 vs 5 vs 10-20 vs 90 seconds...they all have different results. This 90-second cycle remedy comes straight from SonicWALL engineering - we are Platinum partners and get access to engineering KB that general public does not. This case is extremely rare (I very, very rarely see a bricked SonicWALL), and I've never come across the default colors flashing of each LED category as you described. In any case, I have remedied classic bricked LED symptoms before using this 90-second cycle, which is why I wanted you to at least try it before throwing in the towel.
http://community.spiceworks.com/topic/105234-sonicwall-pro-1260-bricked-i-can-t-reset-it-after-spontaneous-power-loss