Well since you changed the Star entity to a planet entity coronas, skyboxes and anything unique to a star can no longer be used.  Remember you also need to go into to the galaxyscenario config file and make sure that you place the new blue star (planet version) as a spawnable planet and not a star otherwise it will still not work.  Here is what you would do to get the same texture and mesh of a star to be colonizable.  Take a look at what I changed and then just go do trial and error until you get it just the way you like it.

TXT
entityType "Planet"
meshInfoCount 1
meshInfo
    typeNameStringID "IDS_PLANETTYPE_VOLCANIC"
    asteroidTemplate "Sparse"
    dustCloudTemplate "PuffySparse"
    meshName "Star_Blue"
    cloudColor ffed8b3b
    nullMeshRadius 0.000000
    nullMeshParticleEffect ""
    hudIcon "HUDICON_STAR_BLUE"
    smallHudIcon "HUDICONSMALL_STAR_BLUE"
    infoCardIcon "INFOCARDICON_STAR_BLUE"
    mainViewIcon "MAINVIEWICON_STAR_BLUE"
    undetectedMainViewIcon "MAINVIEWICON_STAR_BLUE"
    picture "STARPICTURE_BLUE"
minZoomDistanceMult 1.250000
glowColor ff008bff
ringColor ffed8b3b
cloudLayerTextureName "PlanetCloudLayer"
planetResourceSetupInfo
    asteroidSpawnAngleVariance 3.141593
    totalMaxResourceAsteroids 5
    metalResourceAsteroidSetup
        minCount 2
        maxCount 4
        extractionRate 0.400000
        refineryRate 0.060000
        maxRefineryCount 3
    crystalResourceAsteroidSetup
        minCount 0
        maxCount 0
        extractionRate 0.000000
        refineryRate 0.000000
        maxRefineryCount 0
    neutralMetalResourceAsteroidSetup
        minCount 0
        maxCount 0
        extractionRate 0.000000
        refineryRate 0.000000
        maxRefineryCount 0
    neutralCrystalResourceAsteroidSetup
        minCount 0
        maxCount 0
        extractionRate 0.000000
        refineryRate 0.000000
        maxRefineryCount 0
isAsteroid FALSE
healthRegenRate 6.000000
planetUpgradeDef
    path:Population
        stageCount 3
        stage
            price
                credits 0.000000
                metal 0.000000
                crystal 0.000000
            upgradeTime 0.000000
            maxPopulation 10.000000
            populationGrowthRate 0.125000
            developmentTaxPenalty -3.000000
        stage
            price
                credits 450.000000
                metal 150.000000
                crystal 75.000000
            upgradeTime 45.000000
            maxPopulation 30.000000
            populationGrowthRate 0.125000
            developmentTaxPenalty -1.250000
        stage
            price
                credits 550.000000
                metal 175.000000
                crystal 125.000000
            upgradeTime 60.000000
            maxPopulation 70.000000
            populationGrowthRate 0.125000
            developmentTaxPenalty 0.000000
    path:CivilianModules
        stageCount 3
        stage
            price
                credits 0.000000
                metal 0.000000
                crystal 0.000000
            upgradeTime 0.000000
            maxModuleSlotCount:Civilian 8.000000
            maxModuleConstructorCount 0
        stage
            price
                credits 450.000000
                metal 150.000000
                crystal 75.000000
            upgradeTime 45.000000
            maxModuleSlotCount:Civilian 14.000000
            maxModuleConstructorCount 1
        stage
            price
                credits 550.000000
                metal 175.000000
                crystal 125.000000
            upgradeTime 60.000000
            maxModuleSlotCount:Civilian 20.000000
            maxModuleConstructorCount 1
    path:TacticalModules
        stageCount 3
        stage
            price
                credits 0.000000
                metal 0.000000
                crystal 0.000000
            upgradeTime 0.000000
            maxModuleSlotCount:Tactical 10.000000
            maxModuleConstructorCount 1
        stage
            price
                credits 450.000000
                metal 150.000000
                crystal 75.000000
            upgradeTime 45.000000
            maxModuleSlotCount:Tactical 20.000000
            maxModuleConstructorCount 2
        stage
            price
                credits 550.000000
                metal 175.000000
                crystal 125.000000
            upgradeTime 60.000000
            maxModuleSlotCount:Tactical 35.000000
            maxModuleConstructorCount 3
    path:Home
        stageCount 2
        stage
            price
                credits 0.000000
                metal 0.000000
                crystal 0.000000
            upgradeTime 0.000000
            isHomePlanet FALSE
            homePlanetTaxRateBonus 0.000000
        stage
            price
                credits 2000.000000
                metal 300.000000
                crystal 200.000000
            upgradeTime 75.000000
            isHomePlanet TRUE
            homePlanetTaxRateBonus 2.000000
    path:ArtifactLevel
        stageCount 3
        stage
            price
                credits 0.000000
                metal 0.000000
                crystal 0.000000
            upgradeTime 0.000000
        stage
            price
                credits 450.000000
                metal 150.000000
                crystal 75.000000
            upgradeTime 45.000000
        stage
            price
                credits 550.000000
                metal 175.000000
                crystal 125.000000
            upgradeTime 60.000000
    path:Infrastructure
        stageCount 4
        stage
            price
                credits 0.000000
                metal 0.000000
                crystal 0.000000
            upgradeTime 0.000000
            maxHealth 1500.000000
        stage
            price
                credits 450.000000
                metal 150.000000
                crystal 75.000000
            upgradeTime 45.000000
            maxHealth 3000.000000
        stage
            price
                credits 550.000000
                metal 175.000000
                crystal 125.000000
            upgradeTime 60.000000
            maxHealth 4500.000000
        stage
            price
                credits 650.000000
                metal 200.000000
                crystal 175.000000
            upgradeTime 75.000000
            maxHealth 6000.000000
ringsChance 0.050000
isColonizable TRUE
planetTypeForResearch "Volcanic"
skyboxScalarsCount 5
skyboxScalars
    diffuseScalar 1.000000
    ambientScalar 0.000000
skyboxScalars
    diffuseScalar 0.400000
    ambientScalar 0.600000
skyboxScalars
    diffuseScalar 0.900000
    ambientScalar 0.370000
skyboxScalars
    diffuseScalar 0.500000
    ambientScalar 0.800000
skyboxScalars
    diffuseScalar 1.000000
    ambientScalar 0.250000
requiredPlanetBonusesCount 0
possibleRandomPlanetBonusesCount 10
bonus "PlanetBonusAcidAtmosphere"
bonus "PlanetBonusCavernSystem"
bonus "PlanetBonusHighGravity"
bonus "PlanetBonusIonicStorms"
bonus "PlanetBonusMetalMiners"
bonus "PlanetBonusPenalColony"
bonus "PlanetBonusRareMetalDeposits0"
bonus "PlanetBonusStrictSecurity"
bonus "PlanetBonusThermalLift"
bonus "PlanetBonusWeaponTestGrounds"
ambienceSoundID "EFFECT_PLANETAMBIENCE_LOOP"
renderAsVolcanic TRUE
ShieldMeshName "Shield_PlanetSmall"
moveAreaRadius 60000.000000
hyperspaceExitRadius 50000.000000
isWormhole FALSE
minShadow 0.000000
maxShadow 0.000000
ability:0 ""
ability:1 ""
ability:2 ""
ability:3 ""