Why BIOS is in Blue colour? Why BIOS isnt safe ?

These are some notable attacks carried out against BIOS systems:

Chernobyl Attack (1998) – Also known as CIH or Spacefiller was the first major attack on BIOS systems. This virus installs on the windows memory and hooks into file access calls and infects all the currently executing programs. Then the virus tries to flash the BIOS rom by filling it with zeros. The other payload infects the Master Boot Record (MBR) by filling the first megabyte of the hard disk with zeros.

Mebromi (2012) – Is made up of a BIOS rootkit, MBR rootkit, Trojan downloader and PE infector. This Trojan deletes a specific registry value and checks for the BIOS manufacturer. If it’s Award BIOS, it then infects the BIOS ROM and in turn infects the Master BOOT Record (MBR) and alters it allowing the execution of an infected program at each Operating System start-up.

And why BIOS is in Blue , you find it here.