in flow_color.py [0:0]
def makeColorwheel():
# color encoding scheme
# adapted from the color circle idea described at
# http://members.shaw.ca/quadibloc/other/colint.htm
RY = 15
YG = 6
GC = 4
CB = 11
BM = 13
MR = 6
ncols = RY + YG + GC + CB + BM + MR
colorwheel = np.zeros([ncols, 3]) # r g b
col = 0
#RY
colorwheel[0:RY, 0] = 255
colorwheel[0:RY, 1] = np.floor(255*np.arange(0, RY, 1)/RY)
col += RY
#YG
colorwheel[col:YG+col, 0]= 255 - np.floor(255*np.arange(0, YG, 1)/YG)
colorwheel[col:YG+col, 1] = 255;
col += YG;
#GC
colorwheel[col:GC+col, 1]= 255
colorwheel[col:GC+col, 2] = np.floor(255*np.arange(0, GC, 1)/GC)
col += GC;
#CB
colorwheel[col:CB+col, 1]= 255 - np.floor(255*np.arange(0, CB, 1)/CB)
colorwheel[col:CB+col, 2] = 255
col += CB;
#BM
colorwheel[col:BM+col, 2]= 255
colorwheel[col:BM+col, 0] = np.floor(255*np.arange(0, BM, 1)/BM)
col += BM;
#MR
colorwheel[col:MR+col, 2]= 255 - np.floor(255*np.arange(0, MR, 1)/MR)
colorwheel[col:MR+col, 0] = 255
return colorwheel