[Chimera-users] how to color an model by an attribute in chimerax

Dear all, I wish to color an model by an attribute in chimerax. The attribute is the entropy which is calculted by an external software. I wrote the entropy values of each residue in a text file (attr.txt) like the following: attribute: entropy match mode: 1-to-1 recipient: residues :1 0.0 :2 0.0014948 :3 0.0090952 :4 0.0004805 :5 0.1102497 :6 0.0095258 :7 0.0008226 :8 0.0042205 :9 0.0037255 :10 0.0006678 :11 0.0027988 :12 0.0193925 :13 0.0153925 :14 0.0052115 :15 0.0020136 .......... However, when I input the command "color byattr attr.txt", I get the following error information: "No known/Registered attribute attr.txt" Could anyone tell me what is the correct way to do this? With many thanks. Best regards