This apparently was a text mode not a graphics mode. It would have been a tweaked text mode since the standard mode 3 text mode that you can set via int 10h is

This apparently was a text mode not a graphics mode. It would have been a tweaked text mode since the standard mode 3 text mode that you can set via int 10h is 720x400. The energy star logo was also displayed in text modes - by using custom font glyphs!