Figure 1 shows the measured Color Gamuts for the Galaxy Tab S Screen Modes along with the Standard sRGB / Rec.709 Color Gamut in black. The outermost white curve is the limits of human color vision - the horseshoe is the pure spectral colors and the diagonal is the Line of Purples. A given display can only reproduce the colors that lie inside of the triangle formed by its primary colors. Highly saturated colors seldom occur in nature so the colors that are outside of the Standard Gamut are seldom needed and are unlikely to be noticed or missed in the overwhelming majority of real images. Note that consumer content does not include colors outside of the Standard Gamut, so a display with a wider Color Gamut cannot show colors that aren't in the original and will only produce inaccurate exaggerated on-screen colors. The dots in the center are the measured color of White for each of the Screen Modes along with the D65 Standard White, which is marked as a white circle. To deliver accurate image colors for standard consumer photo and video content the display must match the Standard Color Gamut and the Standard Color of White.
The Basic Mode is the closest to the sRGB / Rec.709 Standard and is the most color accurate Screen Mode for standard consumer content, while the Adapt Display Mode has a Wide Color Gamut and is intentionally vivid. The AMOLED Photo Mode is close to the Adobe RGB Gamut that is used with high-end digital cameras and advanced imaging applications.
Note that some of the Screen Modes are similar and their Gamuts and White Points overlap in the Figure.