But can i change the color based on perticular time intervel? .....for example after 30 minutes colour of line in tree view automatically get change....

Hello Yojana walnuj,

You can change the color of tree view conditionally/based on field value.

odoo supports following decoration attributes on tree views.

'decoration-bf',

'decoration-it',

'decoration-danger',

'decoration-info',

'decoration-muted',

'decoration-primary',

'decoration-success',

'decoration-warning',

You can use it like this  decoration-muted="state=='cancel'" as an attribute in the tree view definition.

I hope this may help you. 

Thanks