Dim variable1 As String
Dim variable2 As String
Dim variable3 As String
variable1 = "pepe"
variable2 = "Juan"
variable3 = "antonio"
RichTextBox1.SelColor = vbRed
RichTextBox1.SelText = variable1 & " "
RichTextBox1.SelColor = vbBlack
RichTextBox1.SelText = variable2 & " "
RichTextBox1.SelColor = vbRed
RichTextBox1.SelText = variable3
RichTextBox1.SelColor = vbBlack