Just for a handful of silver he left us,
Just for a riband to stick in his coat—
Found the one gift of which fortune bereft us,
Lost all the others she lets us devote;
They, with the gold to give, doled him out silver,
So much was theirs who so little allowed;
How all our copper had gone for his service!
Rags—were they purple, his heart had been proud!
We that had loved him so, followed him, honoured him,
Lived in his mild and magnificent eye,
Learned his great language, caught his clear accents,
The purple rags signify the aspirations of the leader. Struggling artists may wear  metaphorically  “ragged” clothing, but for Wordsworth clothes were  purple , the colour of royalty. 
 It is known that Wordsworth had a sizeable ego. His talent was admirable but his opinion of himself huge; hence his “heart had been proud”. Browning and his contemporaries were aware of his failings.
The Lost Leader