Not dark silk covers on light upholstery --
I've had light silk on dark, but that wouldn't help...

But your 'blue-green underarms' reminds me of a story when my DS13 was little. I got a call from his preschool saying he just wouldn't stop fussing and seemed unable to walk, so they were taking him to the emergency room. Panic! Of course, I left work immediately and met the teacher's aid there. And yes, he was crying and fussing and clearly seemed to be in a lot of pain. When the nurse came into the room, we removed DS's shirt so she could examine him and his shoulders were dark purple -- they looked horribly bruised! I caught her look and gasp of horror before I realized why his shoulders were purple -- cheap dye from the souvenier shirt we had just brought back for him from Mexico. A little Tylenol cleared up DS's pain (toxic synovitis).