Syntax file, theme and testfile for coloring of nesting blocks.

Test.sublime-syntax

%YAML 1.2
---
# See http://www.sublimetext.com/docs/3/syntax.html
file_extensions:
  - test
scope: source.test
contexts:
  main:
    #Only Alpha and Beta can be base level
    - match: (alpha)\s+=\s+({)
      captures:
        1: alpha
        2: brace.open
      push: alpha_block

    - match: (beta)\s+=\s+({)
      captures:
        1: beta
        2: brace.open
      push: beta_block

  #Alpha can only contain Beta
  alpha_block:
    - meta_scope: alpha.block
    - match: 'beta'
      push: beta_block
    - include: end

    - match: '\w'
      push: invalid

  #Beta can contain Alpha or Charlie
  beta_block:
    - meta_scope: beta.block

    - match: (alpha)\s+=\s+({)
      captures:
        1: alpha
        2: brace.open
      push: alpha_block

    - match: (charlie)\s+=\s+({)
      captures:
        1: charlie
        2: brace.open
      push: charlie_block

    - include: end
    - match: '\w'
      push: invalid
  #Charlie can only contain Beta
  charlie_block:
    - meta_scope: charlie.block
    - match: (beta)\s+=\s+({)
      captures:
        1: beta
        2: brace.open
      push: beta_block
      
    - include: end
    - match: '\w'
      push: invalid
  end: 
    - match: '}'
      pop: true

  invalid:
    - meta_scope: invalid
    - include: end
      

testing.test

alpha = {
	beta = {
		charlie = {
		}
	}
}

alpha = {
	beta = {
		alpha = {	
			beta = {
				alpha = {
					beta = {
						charlie = {

						}
					}
				}
			}
		}
	}
}

alpha = {
	alpha = {

	}
}

alpha = {
	charlie = { 

	}
}

TestingTheme.tmTheme

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
	<key>name</key>
	<string>Testing Theme</string>

	<key>settings</key>
	<array>


		<dict>
			<key>settings</key>
			<!-- General editor color settings   -->
			<dict>
				<key>background</key>
				<string>#000000</string>
				<key>caret</key>
				<string>#A7A7A7</string>
				<key>foreground</key>
				<string>#F8F8F8</string>
				<key>invisibles</key>
				<string>#CAE2FB3D</string>
				<key>lineHighlight</key>
				<string>#FFFFFF0D</string>
				<key>selection</key>
				<string>#DDF0FF33</string>
			</dict>
		</dict>

		<!-- Alpha -->
	    <dict>
	        <key>name</key>
	        <string>Alphas</string>

	        <key>scope</key>
	        <string>alpha</string>

	        <key>settings</key>
	        <dict>
	            <key>foreground</key>
	            <string>#b732ff</string>
	        </dict>
	    </dict>

	    <!-- Beta -->
	    <dict>
	        <key>name</key>
	        <string>Betas</string>

	        <key>scope</key>
	        <string>beta</string>

	        <key>settings</key>
	        <dict>
	            <key>foreground</key>
	            <string>#4a32ff</string>
	        </dict>
	    </dict>

	    <!-- Charlie -->
	    <dict>
	        <key>name</key>
	        <string>Charlies</string>

	        <key>scope</key>
	        <string>charlie</string>

	        <key>settings</key>
	        <dict>
	            <key>foreground</key>
	            <string>#77f231</string>
	        </dict>
	    </dict>

	    <dict>
	        <key>name</key>
	        <string>Invalids</string>

	        <key>scope</key>
	        <string>invalid</string>

	        <key>settings</key>
	        <dict>
	            <key>foreground</key>
	            <string>#ff0000</string>
	        </dict>
	    </dict>
	</array>
</dict>
</plist>