i think you can use represent on this
e.g.
for reference link :
db.employee.bank.represent = lambda bank, field: \
A(bank.bank, _title=T("eBanking"), _target="_blank", _href="%s" % bank.ebanking) if bank else ''
for colored value
db.product.status.represent = lambda status, field: SPAN(product_status[status], _class = 'text-success' if status == 'Sold' else 'text-warning' if status == 'Hold' else 'text-error')
best regards,
stifan