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glClear alpha on render target

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Hello all,

I am rendering brush strokes in an application to a secondary framebuffer to later render them onto the main framebuffer. However, I am getting weird behavior when clearing the framebuffer. The alpha channel doesn't appear to clear to 0. When I render it, the texture is completely white with alpha of 1.0 it seems. Code below:

// clears the brush strokes from the secondary framebuffer
- (void) clearBrushStrokes
glBindFramebufferOES(GL_FRAMEBUFFER_OES, renderFrameBuffer);
glClearColor(1.0, 1.0, 1.0, 0.0);
glBindFramebufferOES(GL_FRAMEBUFFER_OES, viewFramebuffer);

// snippet of creation of the render texture
glGenFramebuffersOES(1, &renderFrameBuffer);
glBindFramebufferOES(GL_FRAMEBUFFER_OES, renderFrameBuffer);
glGenTextures(1, &renderTexture);
glBindTexture(GL_TEXTURE_2D, renderTexture);

NSInteger deviceSize = [iChalkDrawingModel sharediChalkDrawingModel].powerOfTwoSize;

glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, deviceSize, deviceSize, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);


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