The image contains a 16x13 matrix of 4-digit numbers. All of them except one begin with the digit 0. All but two of them end in an even digit. The digit 7 never appears in the third position of any entry in the table. 14:13 PM is an odd time.
After a long spell with no progress, the AntiRiddle Team offered a hint that the numbers in the matrix are wavelengths of light in nanometers. Coloring in the entries with values in the visible spectrum may lead to the long-sought solution. It appears that only the three primary colors are required.
One of the three color areas in the matrix features an interesting color corresponding to a wavelength of 555 nm. This is the color that subectively appears brightest to the human eye, and is the reference point for the unit of luminosity known as the candela. It is not yet known whether this discovery is part of the solution.
After another long spell of dithering around with the color patches, several intrepid puzzle solvers began comparing them to the flags of NATO nations. Eventually this line of investigation paid off. One of the color patches corresponds to the flag of a non-NATO country. That's the odd one out.
'1413' appears in the table of numbers at R3C6. The only other odd entry is '0143' at R13C16. But that's a red herring (no pun intended). Figure out which non-NATO country is represented by a flag with blue, white, and red stripes.