In[1]: A=XYZ(1.0,0.0,0.0)
B=XYZ(0.0,1.0,0.0)
linspace(A,B,40)
Out[1]:

In[2]: A=xyY(1.0,0.0,1.0)
B=xyY(0.0,1.0,1.0)
linspace(A,B,40)
Out[2]: no method weighted_color_mean(Float64, xyY, xyY)
while loading In[2], in expression starting on line 9
in linspace at /Users/jiahao/.julia/v0.3/Color/src/utilities.jl:57