Pamela Anderson is grilled out nicely ... in her white tee.

PamBruise3.jpgOur photogs snapped some pics of Pamela Anderson in Malibu on Wednesday (left and above), and for the fourth time in recent weeks we caught her in a weird, over-sized white T-shirt "dress."

Whether it's flip-flops or boots, Pam always pairs her tee with tan footwear.

But other than an appropriate color palette, Pam was a bit of a general mess -- not only was she wearing this get-up again, she also had a strange bruise on her forehead -- what happened?!? -- and, her tee is 100 percent see-through.

We can see her bra and her g-string (see photos in our gallery below.) Two words, Pam -- "nude underwear."