Check your jumper settings on your motherboard. If you added a 030/25 and it was a original 030/16 you may have to set the jumpers for 25mhz and if it has an fpu you may have to set the jumpers correct for that too. I remember when I added a 040/25 ages ago I came up with a similar red/yellow flashing as you described.
Also if your able to boot at all and you actually have some fast memory in your 3000 and get to the workbench try running a program called SCRAMmer and do a ram check from the ram test section. And read the SCRAMmer guide lots of useful information in there about scram,zip,dip memory and the proper way to configure your ram.
