Rendering A Virtual Isothermal Bitmap?

The short is that I have a temperature model that calculates steel temperatures inside of a furnace at specific points inside a cross section. Typically, the nodes are 7x11, but I'm using a 3x3 here for simplicity. What I've done (and shout out if there's a better way) is to create an in-memory bitmap of that size (3x3), and set each pixel to a specific temperature-based color. Then I the form's Paint event handler to get a graphics object and render the bitmap to the size of the form's client area. Here's my simple code:

Public Class Form1
Private Const m_PixelRows As Integer = 3
Private Const m_PixelColumns As Integer = 3

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