curious yellow or black?

wats a good base coat for the yellow? i painted the test panel over gray primer and it just dont lok like curious yellow to me.

I just used Grey, It worked fine. You will notice that the color is odd in that sometimes it's greenish and others it's yellow.

When the sun hits it directly it's very Yellow, but shade and night show the green much more. here is a pic showing the green more.

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