If you are re-decalling, it might be worth taking one of the decals in to try to match the blue to the colour of the decal.  The existing blue on the machine may be different due to 18 years of fade and dirt??????  At least that way you should get the backbox close to the decal.

we take them to out local paint shop , they used to laugh at us with pins on the ute as we asked for colour matches !