1. A correcting method for a display apparatus, implemented in a non-transitory computer readable medium, comprising: a) measuring respective color performances of the display apparatus for N original grayscale combinations, to generate N measurement results, where N is a positive integer greater than 1; b) utilizing a set of color blending equations for M original grayscale combinations according to the N measurement results to generate M blended results, where M is a positive integer; c) establishing a color performance database comprising (N+M) color performances according to the N measurement results and the M blended results; d) identifying P color performances respectively most approximate to a P predetermined target color performances from the color performance database, wherein P is a positive integer; wherein, the P target color performances correspond to P target grayscale combinations, and the identified P color performances correspond to P original grayscale combinations in the (N+M) original grayscale combinations; and e) establishing a look-up table (LUT) according to the P target grayscale and the corresponding P original grayscale combinations; and f) controlling a driver circuit of the display apparatus to send out an original grayscale combination corresponding to a target grayscale combination determined using the LUT with an inputted grayscale combination as an index, wherein a maximum grayscale value that the display apparatus supports is G MAX , and the N original grayscale combinations comprises (0, 0, 1), (0, 0, 2). .. (0, 0, G MAX ), (0, 1, 0), (0, 2, 0). .. (0, G MAX , 0), (1, 0, 0), (2, 0, 0). .. (G MAX , 0, 0) and (0, 0, 0), wherein one of the M original grayscale combinations is (R 0 , G 0 , B 0 ), the blended result is (X′,Y′,Z′), and the set of color blending equations comprises: 
 X′=X ( R 0 ,0,0)+ X (0, G 0 ,0)+ X (0,0, B 0 ), 
 Y′=Y ( R 0 ,0,0)+ Y (0, G 0 ,0)+ Y (0,0, B 0 ), 
 Z′=Z ( R 0 ,0,0)+ Z (0, G 0 ,0)+ Z (0,0, B 0 ), wherein, X(R 0 ,0,0), Y(R 0 ,0,0) and Z(R 0 ,0,0) represent the color performances of an original grayscale combination (R 0 ,0,0) in a CIE XYZ color space; X(0,G 0 ,0), Y(0,G 0 ,0) and Z(0,G 0 ,0) represent the color performances of an original grayscale combination (0,G 0 ,0) in the CIE XYZ color space; and X(0,0,B 0 ), Y(0,0,B 0 ) and Z(0,0,B 0 ) represent the color performances of an original grayscale combination (0,0,B 0 ) in the CIE XYZ color space.