Count rate curves of GX 339-4 with Insight-HXMT LE (2 − 4 keV) and (4 − 8 keV) data shown in the panel (a) and (b), respectively. Each point represents one day. The red stars represent the days in the HIMS and the blue triangles represent those in the SIMS. The hardness ratios are calculated with (4 − 8 keV)/(2 − 4 keV) and shown in the panel (c). The solid line marks the source in the transition from the LHS to the HIMS, and the dotted line marks the source in the transition to the SIMS.