The Ladonian Flag, also known as “the Glorious Green”, was standardised by Hendrik Lönngren in February of 2008.

The flag is a green field with a green cross. The background and the cross have the same colour, which is expressed in sRGB: 0, 144, 0 (#x009000). The flag is 13 by 21 units in height and length, the cross arms 3 units. Horizontal parts is 5 : 3 : 13, vertical 5 : 3 : 5. As is the nature of the Fibonacci numbers, the flag proportion 21:13 is near the Golden Ratio 1.618.

On physical flags, the stitching on the fabric makes the cross discernible. In 2D graphics or on flags that are screen printed (as opposed to sewn or embroidered), the cross can be very difficult to see, so it is acceptable to use a very light white outline around the cross (see Figure A).