I turned off the light source, but the custom textures still have color discrepancies; they are still greyish. I also tried setting the clock time

Actually, I hope to eliminate the color discrepancies, but I tried setting viewer.clock.currentTime = Cesium.JulianDate.fromIso8601("2021-11-09T04:27:37Z"); viewer.scene.lightingModel = Cesium.LightingModel.UNLIT; viewer.scene.sun.show = false; viewer.scene.globe.enableLighting = false; viewer.scene.globe.enableLighting = false; viewer.shadows = false; viewer.scene.sun.show=false; viewer.scene.moon.show=false; viewer.scene.skyAtmosphere.show=false; viewer.scene.fog.enable=false;

vertexShaderText: void vertexMain(VertexInput vsInput, inout czm_modelVertexOutput vsOutput) { v_normalMC = vsInput.attributes.normalMC; v_st=vsInput.attributes.positionMC ; },
fragmentShaderText: void fragmentMain(FragmentInput fsInput, inout czm_modelMaterial material) { vec2 texCoord = fsInput.attributes.texCoord_0; if(texture(u_texture, texCoord).a>0.0){ material.diffuse = texture(u_texture, texCoord).rgb; } }
This code looks correct.

It seems that the color is also incorrect, did I miss some parameter settings?

material.diffuse = czm_srgbToLinear(vec3(1.0,105.0/255.0,105.0/255.0));
This can solve the problem.