Draw Meas colors remapped in 16-bit TIFFs

[demisjohn]

If try "Draw Measurement - Line" in a 16-bit TIFF, set to Green text on Black BG, just get a funny grey shadowy line & box, no text. Had to convert imager to Type> RGB for DrawMeas. to draw properly.

Maybe should remap colors into the colorspace of the image, or pop a warning?

[demisjohn]

Example image, with 2 attempts done in 16-bit TIFF< and one after setting image to RGB.