All these charts use Humbrol paints as the bench-mark, so if you want to convert from Heller to Vallejo then you'll have to go via Humbrol.
I have tried to be as accurate as possible but I have to point out that the conversions and the colours used in the charts are to be used as a guide only as it is impossible to be totally accurate for several reasons mainly because monitors, printers and the good old fashioned human eye vary so much. Anyway, I hope these prove useful to you.
Click on the logo for the brand you wish to view (Revell, for example) and you'll see a two charts, one converting from Revell to Humbrol and one converting from Humbrol to Revell. If the image is too small then just click on it to zoom in.
A listing of the RLM (Reichsluftfahrtministerium - the German Ministry of Aviation) paint colours.
Originally this chart was requested by a colour blind gentleman who had trouble selecting the nearest colours within the greens. After a little research I found that a large proportion of modellers have some degree of colour blindness and so this chart became more and more important to finish. Although I'm not colour blind myself, I still find this to be a very useful chart.
A chart to convert the old Humbrol Authentic range, which I think was also known as Master Modellers Authentic Colours, into the modern Humbrol range.
Convert from Humbrol to Gunze-Sangyo.