Should accents be used before or after boldface?

Question

Formally speaking, should accents above variables (e.g. tildes, hats and dots; $\tilde a,\hat a,\dot a$) be used before or after a boldface command when I want to use them on a vector? So what is correct in the following for lines; the ones on the left (accent before boldface), or the ones on the right (accents after boldface, making the accents themselves boldface as well)? \begin{align} \tilde{\mathbf{a}},\mathbf{\tilde{a}}\\ \hat{\mathbf{a}},\mathbf{\hat{a}}\\ \dot{\mathbf{a}}, \mathbf{\dot{a}} \end{align}