non ral colour gelcoats for grp?

[baz-r]

i have been looking for my ideal colour for my grp and im a bit stuck as all the blues in the ral range are too dark. im looking for a blue like the old gulf oil race cars had as the main body colour

there are colours i like in the bs code range so i took a look online if resins could be mixed to the right colours
bs 18E50 looks right and some online suppliers list it but what is the chance that bodywork supliers will be able to get bs colours?