What if? - 3/22/19

The puzzle Ol'Fogie has chosen for us today reminds me of thoughts I used to have as a kid ... how could I really know if what I saw as "green" was what somebody else was seeing as "green"?  I understand the science better now, but it's still the kind of question that makes me stop and think. Here's what our guest puzzle-picker had to say:

Visible Spectrum?

Today’s Georgia puzzle is an interesting twist on the color wheel. What if there
are colors you’ve never seen before?!? Explore the possibility with...

ǝpᴉH ǝƃɐʇᴉɹǝH

Tomorrow we'll...