You will find that an unbranded shirt like this is hard to beat.
Pepsi Zero Safety Shirt Large Hi Vis Reflective Workwear Neon Yellow Tee
A crew neck like this one sits comfortably under sweaters or cardigans.
North 15 High Vis LS Safety Work T-Shirt Pocket ASNI Class 2 Yellow Black Sz L
A nice touch is the subtle contrast stitching along the long sleeve hem.
High-Visibility Safety Shirt Chest Pocket Size 2X NEW
You will find that this T-Shirt works just as well for lounging at home.
PIP Hi-Vis Shirt Mens 2XL Safety Yellow Short Sleeve Reflective Tape Class 3
The solid hue gives this T-shirt a smooth, uninterrupted visual flow.