Fanon is not only a critic of colonialism. He has a positive vision, and it is harder to summarize than the critical argument, which is part of why it is less often discussed. But the positive vision is philosophically important, because without it the argument of The Wretched of the Earth is merely a diagnosis. What Fanon is reaching toward, in both books, is something he calls a new humanism.
The concept has to be understood against its alternatives. On one side is the European humanism that the colonial project claimed to be exporting: the universal values of reason, civilization, and human dignity, which, Fanon shows relentlessly, were used as the ideological justification for the violent denial of reason, civilization, and dignity to colonial subjects. European humanism in practice was not universal. It was a racialized particular that presented itself as universal precisely in order to perform its exclusions as the natural order of things. The colonized subject who sought liberation by appealing to European humanist values was asking the colonizer to apply to them the standards the colonizer had already defined in a way that excluded them.
On the other side is the Négritude movement, the assertion of a specifically Black cultural identity as the ground of liberation. Fanon had enormous respect for Négritude as an affective and cultural intervention: the poetry of Aimé Césaire, his teacher and fellow Martinican, changed what it felt like to be Black, and that was no small achievement. But Fanon's philosophical objection to Négritude is consistent throughout his work: the essentialization of Blackness as a positive identity accepts the racial categories the colonial world imposed. It inverts the valuation (Black is good, not bad) but leaves the racial schema in place. Liberation through racial essentialism is liberation within the colonizer's conceptual framework.
The new humanism Fanon calls for is something different: not the universalization of European values and not the celebration of a counter-racial particularity, but the genuine creation of something unprecedented from the experience of anticolonial struggle. As Wikipedia notes, national culture for Fanon is not a historical reality waiting to be recovered in a return to pre-colonial tradition, but is already existing in the present national reality, emerging from the actual experience of struggle, suffering, and collective action. The colonized intellectual's task is not to imitate the colonizer's cultural forms and not to retrieve a pre-colonial past that cannot be simply recovered. It is to address their own people in the reality of their present struggle and to help create cultural forms adequate to the new kind of human being that the anticolonial struggle is bringing into existence.
Fanon ends Black Skin, White Masks with a plea that is also a program: "O my body, always make me a man who questions!" The subject who questions is the subject who has broken out of the trap of both racial categories, who is neither imprisoned in the colonizer's definition of the Black person nor in the counter-essentialist celebration of that definition inverted. It is the subject of the interrogative, permanently open to what the future might make possible. This is philosophically demanding: it requires the colonized subject to refuse both the false recognition the colonial world offers (become like us and we will accept you) and the false comfort of racial essentialism (be proud of what they told you was your inferiority). It requires standing in the difficulty of genuine openness to a human future that has not yet been constituted.