Prohibition of Bersih T shirts is illegal even under ISA

Bersih is not affiliated to any party so you cannot prove that
Bersih's aims are political. You can say that demanding your
constitutional rights is political, but legally it is not defined as
such. Not even implied in this paragraph.
the uniform also must be to organise violence. If peaceful, this act
does not apply.
I am looking for signs that the ISA is against the constitution making
it invalid but this para is not it. It still respects the
constitutional right to PEACEFUL ASSEMBLY, clearly written in the
constitution.
ISA is only an ACT, or law, not as important as the constitution. Any
ACT or law, that violates the constitution is not valid any more.

The Minister may from time to time by order prohibit the
wearing in public places or at meetings or gatherings to which the
public or any section of the public have access, of—
(a) any uniform or dress which signifies association with
any political organization or with the promotion of any
political object; or
(b) any uniform, dress or emblem by members or adherents
of any organization or association specified or described
in the order, whether incorporated or not—
(i) when, in the opinion of the Minister, members of
that organization or association are organized or
trained or equipped for the purpose of enabling
them to be employed in usurping the functions of
the police or of the armed forces; or
(ii) when, in the opinion of the Minister, members of
that organization or association are organized or
trained or equipped for the purpose of enabling
them to be employed for the use or display of
physical force in promoting any political or other
object or in such a manner as to arouse reasonable
apprehension that they are organized or trained or
equipped for that purpose.