Also, you might want to consider edging your camouflage. As it is, it sort of looks like random yellow splotches, or accidental yellow staining, rather than purposely breaking up the profile of the vehicle.
For example, I use grey and ochre, which are likewise similar enough colors to create this problem, and I handle it by
edging with a little bit of rotting flesh, which is a different enough color from either of them to provide the contrast that they need.
Either that, or pick a color that's more different from tan than yellow.